bluuebunny/crossref_metadata_2025 huggingface dataset:
Sex Hormone Levels and Risk of Cardiovascular Events in Postmenopausal Women
Authors: Rexrode Kathryn M. , Manson JoAnn E. , Lee I-Min , Ridker Paul M , Sluss Patrick M. , Cook Nancy R. , Buring Julie E.
Published: September 2003

Background—

Despite diffuse effects of sex hormones on the cardiovascular system, few prospective studies have examined the relationship of plasma androgens and estrogens with risk of cardiovascular disease (CVD) in postmenopausal women.

Methods and Results—

A nested case-control study was performed among women in the Women’s Health Study. Two hundred women who developed CVD were matched 1:1 by age, smoking, and postmenopausal hormone therapy (HT) to controls who remained free of CVD. We measured testosterone, estradiol, and sex hormone binding globulin (SHBG) levels and calculated free androgen index (FAI), free estradiol index, and the FAI/free estradiol index ratio. Results were stratified by HT use. Among HT nonusers, cases had significantly higher androgen profiles (higher median FAI and lower SHBG levels) than controls. After adjustment for age, smoking, use of aspirin, vitamin E, and alcohol, family history of myocardial infarction, and physical activity, nonusers in the lowest SHBG quartile had an OR of 2.25 (95% CI, 1.03 to 4.91) for CVD, and there were significant trends across FAI quartiles (
P
for trend=0.03). Additional adjustment for body mass index, hypertension, diabetes, and elevated cholesterol eliminated associations with SHBG and FAI. Among women using HT, no significant differences in hormones or SHBG were observed among women who developed CVD and controls.

Conclusions—

Among HT nonusers, lower SHBG and higher FAI levels were noted among postmenopausal women who developed CVD events, but this was not independent of body mass index and other cardiovascular risk factors. Estradiol levels were not associated with risk of CVD in HT users or nonusers.
Polymorphism in Glutamate-Cysteine Ligase Modifier Subunit Gene Is Associated With Impairment of Nitric Oxide–Mediated Coronary Vasomotor Function
Authors: Nakamura Shin-ichi , Sugiyama Seigo , Fujioka Daisuke , Kawabata Ken-ichi , Ogawa Hisao , Kugiyama Kiyotaka
Published: September 2003

Background—

The minor −588T allele of polymorphism −588C/T of a modifier subunit gene in glutamate-cysteine ligase (GCLM), a rate-limiting enzyme for glutathione (GSH) synthesis, was associated with lower plasma GSH levels and was a risk factor for myocardial infarction.

Methods and Results—

We examined effects of the −588C/T polymorphism on coronary arterial diameter and blood flow responses to intracoronary infusion of acetylcholine in 157 consecutive subjects who had normal coronary angiograms. In multivariate linear regression analysis with covariates including traditional risk factors, the minor −588T allele had an independent association with impaired dilation or enhanced constriction of epicardial coronary arteries in response to acetylcholine, and it was independently associated with blunted increase in coronary flow response to acetylcholine. In a subgroup of 59 consecutive subjects, constrictor responses of epicardial coronary diameter to intracoronary infusion of
N
G
-monomethyl-
l
-arginine, reflecting the presence of coronary nitric oxide (NO) bioactivity, had an inverse and independent association with the −588T allele in multivariate analysis.

Conclusions—

The −588T polymorphism of the GCLM gene causes a decrease in endothelial NO bioactivity, leading to impairment of endothelium-dependent vasomotor function in large and resistance coronary arteries. The GCL–GSH–NO axis may play a role in the defense system against coronary artery disease.
High-Dose Atorvastatin Enhances the Decline in Inflammatory Markers in Patients With Acute Coronary Syndromes in the MIRACL Study
Authors: Kinlay Scott , Schwartz Gregory G. , Olsson Anders G. , Rifai Nader , Leslie Sally J. , Sasiela William J. , Szarek Michael , Libby Peter , Ganz Peter
Published: September 2003

Background—

Inflammation promotes acute coronary syndromes and ensuing clinical complications. Although statins reduce inflammatory markers in asymptomatic adults or in patients with stable angina, the effect of statins on the markedly heightened inflammation in patients with acute coronary syndromes is unknown.

Methods and Results—

We measured C-reactive protein (CRP), serum amyloid A (SAA), and interleukin 6 (IL-6) in 2402 subjects enrolled the Myocardial Ischemia Reduction with Aggressive Cholesterol Lowering (MIRACL) study. Subjects with unstable angina or non–Q-wave myocardial infarction were randomized to atorvastatin 80 mg/d or placebo within 24 to 96 hours of hospital admission and treated for 16 weeks. The effect of treatment on inflammatory markers was assessed by ANCOVA after adjustment for presenting syndrome, country, and initial level of marker. All 3 markers were markedly elevated at randomization and declined over the 16 weeks in both treatment groups. Compared with placebo, atorvastatin significantly reduced CRP, −83% (95% CI, −84%, −81%) versus −74% (95% CI, −75%, −71%) (
P
<0.0001) and SAA, −80% (95% CI, −82%, −78%) versus −77% (−79%, −75%) (
P
=0.0006) but not IL-6, −55% (95% CI, −57%, −53%) versus −53% (95% CI, −55%, −51%) (
P
=0.3). Reductions in CRP and SAA were observed in patients with unstable angina and non–Q-wave myocardial infarction, with initial LDL cholesterol <3.2 or ≥3.2 mmol/L (125 mg/dL), age ≥65 or <65 years, and in men and women. By 16 weeks, CRP was 34% lower with atorvastatin than with placebo.

Conclusions—

High-dose atorvastatin potentiated the decline in inflammation in patients with acute coronary syndromes. This supports the value of early statin therapy in these patients.
Spontaneous Indices Are Inconsistent With Arterial Baroreflex Gain
Authors: Lipman Ruth D. , Salisbury Julie K. , Taylor J. Andrew
Published: September 2003

Spontaneously occurring, parallel fluctuations in arterial pressure and heart period are frequently used as indices of baroreflex function. Despite the convenience of spontaneous indices, their relation to the arterial baroreflex remains unclear. Therefore, in 97 volunteers, we derived 5 proposed indices (sequence method, α-index, transfer function, low-frequency transfer function, and impulse response function), compared them with arterial baroreflex gain (by the modified Oxford pharmacologic technique), and examined their relation to carotid distensibility and respiratory sinus arrhythmia. The subjects comprised men and women (n=41) aged 25 to 86 years, 30% of whom had established coronary artery disease. Generally, the indices were correlated with each other (except α-index and low-frequency transfer function) and with baroreflex gain. However, the Bland-Altman method demonstrated that the spontaneous indices had limits of agreement as large as the baroreflex gain itself. Even in individuals within the lowest tertile of baroreflex gain for whom baroreflex gain appears to be the most clinically relevant, spontaneous indices failed to relate to baroreflex gain. In fact, for these individuals, there was no correlation between any index and baroreflex gain. Forward stepwise linear regression showed that all spontaneous indices and baroreflex gain were related to respiratory sinus arrhythmia, but only baroreflex gain was related to carotid distensibility. Therefore, these data suggest that spontaneous indices are inadequate estimates of gain and are inconsistent with arterial baroreflex function.
Activation of Adenosine A
1
Receptor Attenuates Cardiac Hypertrophy and Prevents Heart Failure in Murine Left Ventricular Pressure-Overload Model
Authors: Liao Yulin , Takashima Seiji , Asano Yoshihiro , Asakura Masanori , Ogai Akiko , Shintani Yasunori , Minamino Tetsuo , Asanuma Hiroshi , Sanada Shoji , Kim Jiyoong , Ogita Hisakazu , Tomoike Hitonobu , Hori Masatsugu , Kitakaze Masafumi
Published: September 2003

Sympathomimetic stimulation, angiotensin II, or endothelin-1 is considered to be an essential stimulus mediating ventricular hypertrophy. Adenosine is known to protect the heart from excessive catecholamine exposure, reduce production of endothelin-1, and attenuate the activation of the renin-angiotensin system. These findings suggest that adenosine may also attenuate myocardial hypertrophy. To verify this hypothesis, we examined whether activation of adenosine receptors can attenuate cardiac hypertrophy and reduce the risk of heart failure. Our in vitro study of neonatal rat cardiomyocytes showed that 2-chloroadenosine (CADO), a stable adenosine analogue, inhibits protein synthesis of cardiomyocytes induced by phenylephrine, endothelin-1, angiotensin II, or isoproterenol, which were mimicked by the stimulation of adenosine A
1
receptors. For our in vivo study, cardiac hypertrophy was induced by transverse aortic constriction (TAC) in C57BL/6 male mice. Four weeks after TAC, both heart to body weight ratio (6.80±0.18 versus 8.34±0.33 mg/g,
P
<0.0001) as well as lung to body weight ratio (6.23±0.27 versus 10.03±0.85 mg/g,
P
<0.0001) became significantly lower in CADO-treated mice than in the TAC group. Left ventricular fractional shortening and left ventricular dP/dt
max
were improved significantly by CADO treatment. Similar results were obtained using the selective adenosine A
1
agonist
N
6
-cyclopentyladenosine (CPA). A nonselective adenosine antagonist, 8-(
p
-sulfophenyl)-theophylline, and a selective adenosine A
1
antagonist, 8-cyclopentyl-1,3-dipropylxanthine, eliminated the antihypertrophic effect of CADO and CPA, respectively. The plasma norepinephrine level was decreased and myocardial expression of regulator of G protein signaling 4 was upregulated in CADO-treated mice. These results indicate that the stimulation of adenosine receptors attenuates both the cardiac hypertrophy and myocardial dysfunction via adenosine A
1
receptor–mediated mechanisms.
Mild Hypothermia Inhibits Inflammation After Experimental Stroke and Brain Inflammation
Authors: Deng Holly , Han Hyung Soo , Cheng Danye , Sun Guo Hua , Yenari Midori A.
Published: September 2003

Background and Purpose—

We previously showed that mild hypothermia protects against experimental stroke, even when cooling was delayed by 2 hours. Protection may be due in part to inhibiting inflammation. To clarify, we examined leukocyte infiltration, microglial activation, and adhesion molecule expression in models of stroke and pure brain inflammation.

Methods—

Rats underwent 2-hour middle cerebral artery occlusion (MCAO; n=36) or intravenous injection with 5 mg/kg lipopolysaccharide (LPS; n=22). Temperature was lowered to 33°C for 2 hours or kept at 37°C. In MCAO, cooling was applied intraischemically or on reperfusion (delayed). In the LPS model, cooling began after injection. One and 3 days later, brains were assessed for neutrophils, monocytes/microglia, major histocompatibility complex class II antigen, and intercellular adhesion molecule-1 (ICAM-1).

Results—

One day after MCAO, both intraischemic and delayed hypothermia decreased ICAM-1 (51% and 60%, respectively, versus normothermia;
P
<0.001), monocytes (63% and 57%;
P
<0.01), and microglia (55% and 53%;
P
<0.001). Similar decreases were seen at 3 days for ICAM-1 (91% and 93%;
P
<0.001), monocytes (62% and 54%;
P
<0.01), and microglia (55% and 53%;
P
<0.001). In the LPS model, ED-1–positive cells were not observed in the brain, but hypothermia decreased ICAM-1 (26%;
P
<0.05), OX6 (56%;
P
<0.01), and microglia (47%;
P
<0.01) at 1 day.

Conclusions—

Mild hypothermia decreases inflammatory responses in both brain inflammation and stroke, implicating a direct anti-inflammatory effect of cooling. This suggests that hypothermia can attenuate factors contributing to delayed ischemic injury.
Lifetime Cost of Stroke Subtypes in Australia
Authors: Dewey Helen M. , Thrift Amanda G. , Mihalopoulos Cathy , Carter Robert , Macdonell Richard A.L. , McNeil John J. , Donnan Geoffrey A.
Published: September 2003

Background and Purpose—

Little is known about any variations in resource use and costs of care between stroke subtypes, especially nonhospital costs. The purpose of this study was to describe the patterns of resource use and to estimate the first-year and lifetime costs for stroke subtypes.

Methods—

A cost-of-illness model was used to estimate the total first-year costs and lifetime costs of stroke subtypes for all strokes (subarachnoid hemorrhages excluded) that occurred in Australia during 1997. For each subtype, average cost per case during the first year and the present value of average cost per case over a lifetime were calculated. Resource use data obtained in the North East Melbourne Stroke Incidence Study (NEMESIS) were used.

Results—

The present value of total lifetime costs for all strokes was Aus $1.3 billion (US $985 million). Total lifetime costs were greatest for ischemic stroke (72%; Aus $936.8 million; US $709.7 million), followed by intracerebral hemorrhage (26%; Aus $334.5 million; US $253.4 million) and unclassified stroke (2%; Aus $30 million; US $22.7 million). The average cost per case during the first year was greatest for total anterior circulation infarction (Aus $28 266). Over a lifetime, the present value of average costs was greatest for intracerebral hemorrhage (Aus $73 542), followed by total anterior circulation infarction (Aus $53 020), partial anterior circulation infarction (Aus $50 692), posterior circulation infarction (Aus $37 270), lacunar infarction (Aus $34 470), and unclassified stroke (Aus $12 031).

Conclusions—

First-year and lifetime costs vary considerably between stroke subtypes. Variation in average length of total hospital stay is the main explanation for differences in first-year costs.
Islands of the Living Dead
Authors: Ritzer George
Published: September 2003

Two images of the social geography of the McDonaldization of society suggest themselves: Weber's “iron cage” and Foucault's “carceral archipelago.” Although both are helpful in understanding McDonaldization, neither is satisfactory. On one hand, although the cage-like image fits to a degree, it is certainly not an iron cage because escape remains an easy (if not often taken) option for most people. On the other hand, the idea of an archipelago of McDonaldized settings is very attractive, but again, because escape is easy, it cannot be considered a carceral system. It is argued that it is best to see today's McDonaldized systems as “islands of the living dead.” Building on George Romero's sci-fi cult classic, the author contends that although there is much life on these islands, they are also in many senses “dead.” Although it is in the interest of the owners of these settings to make them as dead as possible, those in them often struggle to create as much life as possible.
McDonaldization
Authors: Turner Bryan S.
Published: September 2003

McDonaldization is the most prominent and powerful instance of rationalization in contemporary societies. This article provides a critical assessment of Max Weber's rationalization thesis, develops an alternative to Weber's classical argument, and explores the impact of local cultures on the McDonaldization process. Whereas modernization could be said to follow a linear path of historical development, the differentiation of modernity and the rise of hybrid cultures can be defined as an example of “liquid differentiation.” The argument is that Fordist models of unidimensional rationalization are being replaced by a new dynamic in which there is a permanent but unstable interaction between linear and liquid modernity. This concept of a dynamic is important because it avoids the simple dichotomy between McDonaldized modernity and postmodernity.
From Big Shoulders to Big Macs
Authors: Cain Louis P.
Published: September 2003

Chicago's economy changed over the 20th century from one known for its physical prowess to one known for its mental prowess, from a manufacturing center to a service center. It remained the home of multinational corporations, but in many cases, their production was moved elsewhere. The meatpacking industry is representative of the Chicago economy at the start of the 20th century, whereas McDonald's is consistent with what it had become by the end of the century. It is shown that many of the elements of the McDonaldization hypothesis were present a century ago, particularly in the problems faced by the meatpacking industry.
Identification of genes modulated in multiple myeloma using genetically identical twin samples
Authors: Munshi Nikhil C. , Hideshima Teru , Carrasco Daniel , Shammas Masood , Auclair Daniel , Davies Faith , Mitsiades Nicholas , Mitsiades Constantine , Kim Ryung Suk , Li Cheng , Rajkumar S. Vincent , Fonseca Rafael , Bergsagel Lief , Chauhan Dharminder , Anderson Kenneth C.
Published: September 2003

Genetic heterogeneity between individuals confounds the comparison of gene profiling of multiple myeloma (MM) cells versus normal plasma cells (PCs). To overcome this barrier, we compared the gene expression profile of CD138+ MM cells from a patient bone marrow (BM) sample with CD138+ PCs from a genetically identical twin BM sample using microarray profiling. Two hundred and ninety-six genes were up-regulated and 103 genes were down-regulated at least 2-fold in MM cells versus normal twin PCs. Highly expressed genes in MM cells included cell survival pathway genes such as mcl-1, dad-1, caspase 8, and FADD-like apoptosis regulator (FLIP); oncogenes/transcriptional factors such as Jun-D, Xbp-1, calmodulin, Calnexin, and FGFR-3; stress response and ubiquitin/proteasome pathway–related genes and various ribosomal genes reflecting increased metabolic and translational activity. Genes that were down-regulated in MM cells versus healthy twin PCs included RAD51, killer cell immunoglobulin-like receptor protein, and apoptotic protease activating factor. Microarray results were further confirmed by Western blot analyses, immunohistochemistry, fluorescent in situ hybridization (FISH), and functional assays of telomerase activity and bone marrow angiogenesis. This molecular profiling provides potential insights into mechanisms of malignant transformation in MM. For example, FGFR3, xbp-1, and both mcl-1 and dad-1 may mediate transformation, differentiation, and survival, respectively, and may have clinical implications. By identifying genes uniquely altered in MM cells compared with normal PCs in an identical genotypic background, the current study provides the framework to identify novel therapeutic targets.
Safety and efficacy of factor IX gene transfer to skeletal muscle in murine and canine hemophilia B models by adeno-associated viral vector serotype 1
Authors: Arruda Valder R. , Schuettrumpf Joerg , Herzog Roland W. , Nichols Timothy C. , Robinson Nancy , Lotfi Yasmin , Mingozzi Federico , Xiao Weidong , Couto Linda B. , High Katherine A.
Published: September 2003

Adeno-associated viral (AAV) vectors (serotype 2) efficiently transduce skeletal muscle, and have been used as gene delivery vehicles for hemophilia B and for muscular dystrophies in experimental animals and humans. Recent reports suggest that AAV vectors based on serotypes 1, 5, and 7 transduce murine skeletal muscle much more efficiently than AAV-2, with reported increases in expression ranging from 2-fold to 1000-fold. We sought to determine whether this increased efficacy could be observed in species other than mice. In immunodeficient mice we saw 10- to 20-fold higher levels of human factor IX (hF.IX) expression at a range of doses, and in hemophilic dogs we observed approximately 50-fold higher levels of expression. The increase in transgene expression was due partly to higher gene copy number and a larger number of cells transduced at each injection site. In all immunocompetent animals injected with AAV-1, inhibitory antibodies to F.IX developed, but in immunocompetent mice treated with high doses of vector, inhibitory antibodies eventually disappeared. These studies emphasize that the increased efficacy of AAV-1 vectors carries a risk of inhibitor formation, and that further studies will be required to define doses and treatment regimens that result in tolerance rather than immunity to F.IX.
Survivin regulates hematopoietic progenitor cell proliferation through p21WAF1/Cip1-dependent and -independent pathways
Authors: Fukuda Seiji , Mantel Charlie R. , Pelus Louis M.
Published: September 2003

The cyclin-dependent kinase inhibitor p21WAF1/Cip1 and Survivin enhance granulocyte macrophage colony-forming unit (CFU-GM) cell cycle and proliferation and have been implicated as antiapoptotic proteins. We investigated the relationships between p21 and Survivin in primary CFU-GM and c-kit+, lineage-negative (Lin–) cells and demonstrate p21-dependent and -independent pathways whereby Survivin regulates progenitor cell proliferation. Ectopic Survivin enhanced p21+/+ CFU-GM formation and expansion of c-kit+, Lin– cells, whereas p21 gene loss abrogated these effects, indicating a p21 requirement. A dominant-negative form of Survivin and p21 gene deletion accelerated the loss of CFU-GM upon growth factor deprivation, and wild-type Survivin overexpression inhibited apoptosis of p21+/+ CFU-GM and c-kit+, Lin– cells but not p21–/– cells, suggesting that both Survivin and p21 block apoptosis of progenitors and that Survivin-mediated antiapoptosis requires p21. In contrast to the p21-dependent antiapoptotic effects, Survivin increased the proportion of CFU-GM in S-phase in both p21+/+ and p21–/– cells. Furthermore, modulating Survivin expression increased polyploidy in c-kit+, Lin– cells, which was accentuated by p21 deficiency. These results suggest that the Survivin-p21 axis plays an important role in the proliferation of normal hematopoietic cells and that Survivin regulates apoptosis through a p21 WAF1/Cip1-dependent pathway but may control S-phase entry independent of p21.
Ligation of CD137 receptor prevents and reverses established anergy of CD8+ cytolytic T lymphocytes in vivo
Authors: Wilcox Ryan A. , Tamada Koji , Flies Dallas B. , Zhu Gefeng , Chapoval Andrei I. , Blazar Bruce R. , Kast W. Martin , Chen Lieping
Published: September 2003

T-cell anergy is a tolerance mechanism defined as a hyporesponsive status of antigen-specific T cells upon prior antigen encounter and is believed to play a critical role in the evasion of tumor immunity and the amelioration of allogeneic transplant rejection. Molecular mechanisms in controlling T-cell anergy are less known. We show here that administration of an agonistic monoclonal antibody (mAb) to CD137, a member of the tumor necrosis factor receptor superfamily, prevents the induction of CD8+ cytolytic T-lymphocyte (CTL) anergy by soluble antigens. More importantly, CD137 mAb restores the functions of established anergic CTLs upon reencountering their cognate antigen. As a result, infusion of CD137 mAb inhibits progressive tumor growth that is caused by soluble tumor antigen-induced tolerance in a P815R model. CD137 mAb also restores proliferation and effector functions of anergic alloreactive 2C T cells in a bone marrow transplantation model. Our results indicate that ligation of CD137 receptor delivers a regulatory signal for T-cell anergy and implicate manipulation of the CD137 pathway as a new approach to break T-cell tolerance.
Female donors contribute to a selective graft-versus-leukemia effect in male recipients of HLA-matched, related hematopoietic stem cell transplants
Authors: Randolph Sophia S. B. , Gooley Theodore A. , Warren Edus H. , Appelbaum Frederick R. , Riddell Stanley R.
Published: September 2003

Male recipients of transplants from female (F→M) hematopoietic stem cell donors represent a special group in whom donor T cells that are specific for recipient minor histocompatibility antigens encoded by Y-chromosome genes may contribute to a graft-versus-leukemia (GVL) effect and to graft-versus-host disease (GVHD). We examined the contribution of donor/patient sex to the risk for relapse and GVHD in 3238 patients who underwent HLA-identical sibling hematopoietic stem cell transplantation (HSCT) for hematopoietic malignancies at a single institution. Compared with other sex combinations, male recipients of female transplants had the lowest risk for relapse and the greatest odds for GVHD. Remarkably, after controlling for GVHD as a time-dependent covariate, F→M HSCT still exhibited a lower risk for relapse than other sex combinations, demonstrating a selective GVL effect distinct from that contributed by GVHD. A reduction in relapse after F→M HSCT was observed in patients with chronic myelogenous leukemia (CML), acute myelogenous leukemia (AML), and acute lymphoblastic leukemia (ALL). Taken together, these data suggest that minor H antigens encoded or regulated by genes on the Y chromosome contribute to a selective GVL effect against myeloid and lymphoid leukemias after F→M HSCT.
T cell aggregation induced through CD43: intracellular signals and inhibition by the immunomodulatory drug leflunomide
Authors: Layseca-Espinosa Esther , Pedraza-Alva Gustavo , Montiel José Luis , del Río Roxana , Fierro Nora A , González-Amaro Roberto , Rosenstein Yvonne
Published: September 2003

The CD43 coreceptor molecule has been shown to participate in lymphocyte adhesion and activation. Leukocyte homotypic aggregation results from a cascade of intracellular signals delivered to the cells upon engagement of different cell-surface molecules with their natural ligands. This phenomenon requires an active metabolism, reorganization of the cytoskeleton, and relocalization of cell-surface molecules. The aim of this study was to identify some of the key members of the signaling cascade leading to T lymphocyte homotypic aggregation following CD43 engagement. CD43-mediated homotypic aggregation of T lymphocytes required the participation of Src kinases, phospholipase C-γ2, protein kinase C, phosphatidylinositol-3 kinase, as well as extracellular-regulated kinase 1/2 and p38. Data shown here suggest that these signaling molecules play a central role in regulating actin cytoskeleton remodeling after CD43 ligation. We also evaluated the ability of immunomodulatory drugs such as leflunomide to block the CD43-mediated homotypic aggregation. Leflunomide blocked the recruitment of targets of the Src family kinases as well as actin polymerization, diminishing the ability of T lymphocytes to aggregate in response to CD43-specific signals, suggesting that this drug might control the migration and recruitment of lymphoid cells to inflamed tissues.
TCR subunit specificity of CTLA-4-mediated signaling
Authors: Siu Eric , Carreno Beatriz M , Madrenas Joaquín
Published: September 2003

Cytotoxic T-lymphocyte-associated antigen (CTLA)-4 is an activation-induced receptor that down-regulates T cell responses by antagonizing B7-dependent costimulation and/or by transducing a negative signal. The mechanism of CTLA-4-mediated negative signaling is unknown. Recently, it has been postulated that CTLA-4 inhibits T cell activation by causing specific dephosphorylation of the T cell receptor (TCR)-ζ chain of the antigen-receptor complex through an lck-dependent recruitment of the Src homology-2-containing tyrosine phosphatase-2. To test this hypothesis, we generated stably transfected T cell clones expressing doxycycline-inducible CTLA-4 with CD25:TCR-ζ (CD25-ζ) or CD25:CD3-ɛ (CD25-ɛ) fusion proteins. In these clones, ligation of CD25-ζ or of CD25-ɛ with antibodies against CD25 induced full T cell activation, as illustrated by extracellular signal-regulated kinase (ERK) activation and interleukin (IL)-2 production. More importantly, coligation of CTLA-4 with CD25-ζ or of CTLA-4 with CD25-ɛ in the respectively transfected clones inhibited ERK activation and IL-2 production, demonstrating that CTLA-4 does not specifically inhibit signals from TCR-ζ but can also inhibit signals from CD3-ɛ. Our results suggest that the target specificity of CTLA-4 is determined by its coligation with any given transmembrane receptor rather than by its intracellular mediators.
Two Immunoglobulin G Fragment C Receptor Polymorphisms Independently Predict Response to Rituximab in Patients With Follicular Lymphoma
Authors: Weng Wen-Kai , Levy Ronald
Published: September 2003

Purpose: Although rituximab is now routinely used in the treatment of B-cell non-Hodgkin’s lymphoma, the mechanism of its antitumor effect is not clear. One potential mechanism of action involves antibody-dependent cellular cytotoxicity (ADCC). Two aspects of ADCC influence the effectiveness of this process: the susceptibility of tumor cells and the activation of effector cells via their immunoglobulin G fragment C receptors (FcγRs). Several FcγR polymorphisms have been identified that may affect the killing function of natural killer cells and macrophages.

Patients and Methods: The pretreatment tumor cells from 43 patients with follicular lymphoma were tested for their intrinsic susceptibility to rituximab-mediated ADCC. In addition, the FcγRIIIa (CD16) and FcγRIIa (CD32) polymorphisms were determined in an expanded group of 87 patients. The results were then correlated with clinical outcome of these patients.

Results: No difference was found between the susceptibility of tumors from patients who clinically responded to rituximab versus those who did not respond. Conversely, both the FcγRIIIa 158 valine/valine and the FcγRIIa 131 histidine/histidine genotypes were found to be independently associated with the response rate and freedom from progression.

Conclusion: These data support the hypothesis that ADCC plays an important role in the clinical effect of rituximab at the level of the effector cell. It will be important to include information on Fc receptor polymorphisms in future trials of rituximab therapy.
Activation of NF-κB byToxoplasma gondiicorrelates with increased expression of antiapoptotic genes and localization of phosphorylated IκB to the parasitophorous vacuole membrane
Authors: Molestina Robert E. , Payne T. Matthew , Coppens Isabelle , Sinai Anthony P.
Published: September 2003

Mammalian cells infected with Toxoplasma gondii are resistant to apoptosis induced by a variety of stimuli. We have demonstrated that the host transcription factor NF-κB plays a pivotal role in the T.-gondii-mediated blockade of apoptosis because inhibition is lost in cells lacking the p65 (RelA) subunit of NF-κB (p65–/–). In the present study, we examined the effects of T. gondii infection on NF-κB activation and the expression of genes involved in the apoptotic cascade. Infection of wild-type mouse embryonic fibroblasts (MEFs) with T.-gondii-induced nuclear translocation of the p50 and p65 subunits of NF-κB as examined by immunoblotting of nuclear extracts, immunofluorescence and electrophoretic mobility shift assays. A comparison of apoptotic gene expression profiles from wild-type and p65–/– MEFs revealed distinct patterns of induction in response to T. gondii infection. In particular, the differences seen in the Bcl-2 and IAP families are consistent with the antiapoptotic responses observed in the resistant wild-type cells compared with the sensitive p65–/– fibroblasts. Consistent with NF-κB activation, T. gondii infection promoted phosphorylation of the inhibitor IκB. Interestingly, phosphorylated IκB was concentrated on the parasitophorous vacuole membrane (PVM), suggesting a parasite-directed event. Results from this study suggest that activation of NF-κB plays an important role in stimulation of antiapoptotic gene expression by T. gondii. Furthermore, recruitment of phosphorylated IκB to the PVM implies the presence of intrinsic factor(s) in T. gondii that might be used to manipulate the NF-κB signaling pathway in the host to elicit a survival response during infection.
Probabilistic analysis of braking performance in railways
Authors: Malvezzi M , Presciani P , Allotta B , Toni P
Published: September 2003

To increase safety and efficiency in the management of railway traffic, a new speed control system, named SCMT, is currently being developed by RFI and Trenitalia for the Italian Railways. Other innovative speed supervision systems are being developed in Europe, such as the ETCS/ERTMS, which will also be installed on the new high-speed line Roma-Napoli.

All traffic management systems are generally based on a set of supervision curves relating the allowed velocity of the train to the running distance, in order to ensure the respect of speed restrictions on the line by ‘soft’ or ‘hard’ intervention such as an acoustic and visual warning to the driver (soft) and/or service or emergency braking (hard) in the case of train velocity exceeding the permitted one. To elaborate this set of supervision curves, the on-board unit requires train deceleration depending on time and speed as basic information about the braking behaviour of the train.

The implementation of a speed supervision system requires a preliminary definition of braking models that allow the conversion of the general parameters affecting the braking performances of trains (such as a braked weight percentage, goods/passenger brake position, brake equipment, train length, etc.) into a basic deceleration profile as a function of time, during the deceleration rise phase, and of speed, during fully developed braking. The deceleration used to evaluate braking curves is obtained by applying a proper safety margin to the nominal deceleration value (which depends on train characteristics).

In this paper a probabilistic analysis of train deceleration is carried out, starting from probability distributions of parameters affecting the braking. For the major parameters, the probability distribution was determined on the basis of technical knowledge and experimental results. The aim of this work is to determine the probability that the real deceleration is lower than the nominal value multiplied by a given safety margin.
Wavelet multiresolution analysis for monitoring the occurrence of arcing on overhead electrified railways
Authors: Barmada S , Landi A , Papi M , Sani L
Published: September 2003

A crucial problem for railway companies is the detection of the critical points of the overhead line for predicting excessive wear of the contact wire and for helping maintenance activities. An innovative tool, based on wavelet multiresolution analysis, is proposed in this paper for on-line monitoring of the quality of current collection. Wavelet decomposition of data collected from different measurement systems (e.g. total traction line current or signals acquired from unconventional sensors) can perform an automatic analysis of the data collected and can detect a singular occurrence of arcing due to loss of contact of the pantograph. A relevant outcome of such an analysis is the evaluation of a quantitative index for checking the quality of the current collection via an integral analysis of the multiresolution signal decomposition. Examples of analysis from experimental data are reported in the paper.
Fatigue design of rubber springs used in rail vehicle suspensions
Authors: Luo R. K. , Cook P. W. , Wu W. X. , Mortel W. J.
Published: September 2003

Rubber-to-metal bonded springs are vital antivibration components for rail vehicles. Metacone rubber springs are widely used as a primary spring on a rail vehicle fitted at the wheel axle box. Nowadays the more demanding operating environment has made the design of such components more challenging than ever before. By using an integrated design-simulation-testing procedure it is possible to achieve the maximum fatigue capacity of the suspension components under a very tight space envelope. This note illustrates the procedure to achieve the high performance and the fatigue service life requirements for the suspension components.
A microRNA array reveals extensive regulation of microRNAs during brain development
Authors: KRICHEVSKY ANNA M. , KING KEVIN S. , DONAHUE CHRISTINE P. , KHRAPKO KONSTANTIN , KOSIK KENNETH S.
Published: September 2003

Several hundred microRNAs (miRNAs) have recently been cloned from a wide range of organisms across phylogeny. Despite the high degree of conservation of miRNAs, their functions in general, and in mammals particularly, are just beginning to be defined. Here we show that an oligonucleotide DNA array can be successfully used for the simultaneous analysis of miRNA expression profiles from tissues or cells. From a subset of miRNAs expressed in the brain we designed an oligonucleotide array spotted with probes specific for 44 mature miRNAs. These arrays demonstrated precise regulation of miRNA expression at mammalian brain developmental epochs. About 20% of the probed miRNAs changed significantly in their expression during normal brain development, and two of them, miR-9 and miR-131, were dysregulated in presenilin-1 null mice exhibiting severe brain developmental defects. Transcripts with regulated expression patterns on the arrays were validated by Northern blots. Additionally, a bioinformatic analysis of developmentally regulated miRNAs suggested potential mRNA targets. The arrays also revealed miRNAs distributed to translating polyribosomes in primary neurons where they are likely to modulate translation. Therefore, oligonucleotide arrays provide a new tool for studying miRNA expression in a variety of biological and pathobiological settings. Creating clusters of coexpressed miRNAs will contribute to understanding their regulation, functions, and discovery of mRNA targets.
Determination of lipophilic descriptors of antihelmintic 6,7‐diaryl‐pteridine derivatives useful for bioactivity predictions
Authors: Reta Mario , Giacomelli Liliana , Santo Marisa , Cattana Rosa , Silber Juana J , Ochoa Carmen , Rodriguez Mercedes , Chana Antonia
Published: September 2003

The liquid chromatographic retention factors extrapolated to pure water, k′w, for several 6,7‐diaryl‐pteridine derivatives in both an octadecylsilane (ODS) and an immobilized artiﬁcial membrane column (IAM.PC.DD2), using acetonitrile–aqueous buffer pH = 7.45 as mobile phase, were obtained. The logarithms of the k′w values in the IAM.PC.DD2 column, log k′wIAM, show good correlation with the calculated values of the octanol–water partition coefﬁcients, log Po/w, showing that the chromatographic parameter can be used as lipophilicity descriptor for the studied pteridines. However, interactions other than the lipophilic ones seem to be involved in the ODS column. Previous studies have shown that pteridines have antihelmintic properties. In spite of the complexity of the studied biological system as compared with the chromatographic one, good correlation between the descriptors obtained in the IAM column and biological activity (expressed as the log of the inhibitory concentration required to obtain up to 50% in the reduction of population growth of nematodes, log IC50) was observed. Copyright © 2003 John Wiley & Sons, Ltd.
Determination of melagatran in rabbit plasma by high‐performance liquid chromatography with automated column switching
Authors: Kim Byoung‐Hyoun , Park Sun Young , Choi Nak Hee , Ok Jong Hoa
Published: September 2003

Melagatran is an active thrombin inhibitor showing oral and parenteral bioavailability for antithrombotic therapy. A simple and convenient liquid chromatographic method has been developed and applied to the analysis of melagatran in rabbit plasma. The clean‐up and separation of the sample solutions were performed by automated on‐line column switching HPLC. The method validation shows the suitability of the column switching liquid chromatographic system for the quantitation of melagatran in biological ﬂuids. Copyright © 2003 John Wiley & Sons, Ltd.
The inﬂuence of α1‐acid glycoprotein on collagenase‐3 activity in early rheumatoid arthritis
Authors: Haston J. Louise , FitzGerald Oliver , Kane David , Smith Kevin D.
Published: September 2003

The concentration and glycosylation of α1‐acid glycoprotein (AGP) alter signiﬁcantly during inﬂammation. A deﬁnitive physiological role for AGP remains elusive and is the subject of extensive investigation. This study investigated the inﬂuence of AGP on the activity of collagenase‐3, an important mediator of cartilage destruction in rheumatoid arthritis. AGP was isolated from normal and rheumatoid plasma. Fucosylation was determined by high pH anion‐exchange chromatography; sialylation was assessed following enzymatic digest. Rheumatoid AGP displayed elevated fucosylation and sialylation compared with normal. The inﬂuence of each sample on collagenase‐3 activity was measured ﬂuorometrically. AGP inﬂuenced collagenase‐3 catalysis and collagen binding, with catalytic activity correlating with fucosylation. Rheumatoid AGP exhibited less efﬁcient inhibition than normal plasma AGP. It is hypothesized that AGP within rheumatoid synovial ﬂuid may be inadequate to prevent excessive cartilage destruction and hence may exacerbate the disease process. Copyright © 2003 John Wiley & Sons, Ltd.
Molecular characterization of two host–guest associating hyaluronan derivatives
Authors: Šoltés L. , Mendichi R.
Published: September 2003

Molecular characteristics were determined of two high‐molecular‐weight water‐soluble hyaluronan derivatives, namely β‐cyclodextrin (HA‐β‐CD) and N‐acylurea (EDC‐HA). The weight‐average molecular weight (Mw) of HA‐β‐CD and of EDC‐HA, determined with a multi‐angle light scattering detector connected on‐line to a size exclusion chromatographic system, was respectively 185.3 and 86.8 kDa. However the Mw value determined for the equimolar mixture of the two HA derivatives equaled 556.0 kDa. Similarly, the gyration radius of the above equimolar mixture, Rg = 80.6 nm, was signiﬁcantly greater than the values found for the single HA derivative, i.e. 40.2 nm for HA‐β‐CD and 23.8 nm for EDC‐HA. These data indicate that the two kinds of substituents, bound to the polymeric chains, form host–guest/inclusion complexes resulting in polymacromolecular associates/aggregates. Copyright © 2003 John Wiley & Sons, Ltd.
Quantitative determination of DRF‐1042 in human plasma by HPLC: validation and application in clinical pharmacokinetics
Authors: Upreti Vijay V. , Mamidi Rao N.V.S. , Katneni Kasiram , Srinivas Nuggehally R.
Published: September 2003

A simple and sensitive high‐performance liquid chromatography (HPLC) method has been developed and validated for the determination of DRF‐1042, a novel orally active camptothecin (CPT) analog, in human plasma. The sample preparation was a simple deproteinization with acidiﬁed methanol yielding almost 100% recovery of DRF‐1042. An isocratic reverse‐phase HPLC separation was developed on a Supelcosil‐LC318 column (250 × 4.6 mm, 5 µm) with mobile phase consisting of 1% v/v triethylamine acetate, pH 5.5 and acetonitrile (80:20, v/v) at a ﬂow rate of 1.0 mL/min. The eluate was monitored with a ﬂuorescence detector set at excitation and emission wavelengths of 370 and 430 nm, respectively. The standard curves were linear (r2 > 0.999) in the concentration ranges 5.0–2004 ng/mL. The lower limit of quantiﬁcation (LLQ) of the assay was 5 ng/mL. The mean measured quality control (QC) concentrations (range 5 ng/mL to 40 µg/mL) deviated from the nominal concentrations in the range of −10.5–0.08 and −14.5–7.97%, inter‐ and intra‐day, respectively. The inter‐ and intra‐day precisions in the measurement of QC samples at four tested concentrations, were in the range 0.64–5.89% relative standard deviation (RSD) and 0.33–14.7% RSD, respectively. The method was found to be suitable for measurement of plasma concentrations above the calibration curve after serial dilutions. Stability of DRF‐1042 was conﬁrmed in a battery of studies, viz., on bench‐top, in the auto‐sampler, in the stock solutions, after four quick freeze–thaw cycles, up to one month at −20C in human plasma and up to 2 months in the ex vivo samples. The method is simple, sensitive and reliable and has been successfully implemented to investigate the clinical pharmacokinetics of DRF‐1042 in cancer patients in a phase I clinical trial. Copyright © 2003 John Wiley & Sons, Ltd.
Reversed‐phase liquid chromatographic method for the analysis of aminoglycoside antibiotics using pre‐column derivatization with phenylisocyanate
Authors: Kim Byoung‐Hyoun , Lee Suk Chin , Lee Hye Jin , Ok Jong Hoa
Published: September 2003

A pre‐column derivatization liquid chromatographic method has been developed for the analysis of aminoglycoside antibiotics using phenylisocyanate as a derivatization reagent. Derivatives including kanamycin, neomycin and gentamicin were formed by reaction of the analytes with phenylisocyanate in the presence of triethylamine. Phenylisocyanato groups were attached to corresponding amino groups of aminoglycoside and their molecular mass was conﬁrmed by liquid chromatography–electrospray ionization–mass spectrometry (LC‐ESI‐MS). The experimental conditions for derivatization and separation of aminoglycoside derivatives were optimized and validated. A simple liquid chromatographic method for the determination of aminoglycoside antibiotics was demonstrated. Copyright © 2003 John Wiley & Sons, Ltd.
Improvement of cyclosporin A determination in whole blood by reversed‐phase high‐performance liquid chromatography
Authors: Ouyang Jin , Baeyens Willy R. G. , Duan Jingli , Delanghe Joris
Published: September 2003

A chromatographic method was developed for the determination of cyclosporin A in human whole blood using reversed‐phase HPLC at room temperature. Most previous reports carried out this liquid chromatographic separation at temperatures above 70°C. The present procedure greatly improves the detection limit by controlling peak broadening effects, as well as the lifetime of the column at room temperature. Under optimal conditions and using ketoconazole as an internal standard, the calibration graph was linear in the range of 16–1000 µg/L with a relative standard deviation of 3.72% at 150 µg/L and 2.45% at 300 µg/L (n = 11) of cyclosporin A. The detection limit was of 5.0 µg/L cyclosporin A. By this procedure, cyclosporin A pharmacokinetic parameters in healthy Chinese subjects were studied. The developed method could be applied to the quantiﬁcation of cyclosporin A in human blood samples and allows the study of its pharmacokinetics in routine laboratories. Copyright © 2003 John Wiley & Sons, Ltd.
Versican undergoes speciﬁc alterations in the ﬁne molecular structure and organization in human aneurysmal abdominal aortas
Authors: Theocharis A. D. , Tsolakis I. , Hjerpe A. , Karamanos N. K.
Published: September 2003

Versican is the major matrix proteoglycan in aortic wall and participates in various biological functions of the tissue. In the present study the molecular characteristics of versican isolated from normal human aorta as well as those of versican expressed in aneurysmal aortic tissue were examined. Versican was isolated by combined anion‐exchange and gel permeation chromatography and was further characterized by high‐performance liquid chromatography, polyacrylamide gel electrophoresis and immunoblotting. In both tissues versican is exclusively substituted with chondroitin sulfate chains, in contrast to other human tissues where both chondroitin and dermatan sulfate chains are attached onto versican core proteins. Except for the signiﬁcant decrease in the concentration of versican in the aneurysmal tissue, this PG undergoes speciﬁc alterations in the aneurysmal tissue. The molecular size of versican isolated from diseased tissue is decreased with a simultaneous increase in the ratio of glycosaminoglycan to protein in this tissue. The latter reﬂect the extensive fragmentation of versican in the diseased tissue and most probably the generation of shorter peptides enriched to glycosaminoglycan chains. Although the size of chondroitin sulfate chains is identical in both versican preparations, a signiﬁcant increase in the percentage of 6‐sulfated disaccharides is observed in chondroitin sulfate chains of versican in aneurysmal aortas, which is accompanied by decrease in 4‐sulfated and non‐sulfated units. Copyright © 2003 John Wiley & Sons, Ltd.