bluuebunny/crossref_metadata_2025 huggingface dataset:
Role for Matrix Metalloproteinase-2 in Oxidized Low-Density Lipoprotein–Induced Activation of the Sphingomyelin/Ceramide Pathway and Smooth Muscle Cell Proliferation
Authors: Augé Nathalie , Maupas-Schwalm Françoise , Elbaz Meyer , Thiers Jean-Claude , Waysbort Axel , Itohara Shigeyoshi , Krell Hans-Willi , Salvayre Robert , Nègre-Salvayre Anne
Published: July 2004

Background—

Oxidized LDLs (oxLDLs) and matrix metalloproteinases (MMPs) are present in atherosclerotic lesions. OxLDLs activate various signaling pathways potentially involved in atherogenesis. OxLDLs induce smooth muscle cell (SMC) proliferation mediated by the activation of the sphingomyelin/ceramide pathway and tyrosine kinase receptors. MMPs are also able to induce SMC migration and proliferation in addition to extracellular matrix degradation. The present study was designed to investigate whether MMPs play a role in the mitogenic effect of oxLDLs.

Methods and Results—

OxLDLs induce the release of activated MMP-2 in SMC culture medium. MMP-2 was identified by its 65-kDa gelatinase activity on zymography and by using specific blocking antibodies and MMP-2
−/−
cells. MMP inhibitors (batimastat and Ro28-2653) and the blocking antibodies anti–MMP-2 and anti–membrane type 1-MMP inhibited the oxLDL-induced sphingomyelin/ceramide pathway activation and subsequent activation of ERK1/2 and DNA synthesis but did not inhibit the oxLDL-induced epidermal growth factor receptor and platelet-derived growth factor receptor activation. Exogenously added activated MMP-2 or membrane type 1-MMP-1 triggered the activation of both sphingomyelin/ceramide and ERK1/2 pathways and DNA synthesis. Conversely, suppression of MMP-2 expression in MMP-2
−/−
cells or in SMCs treated by small-interference RNA also blocked both sphingomyelin/ceramide signaling and DNA synthesis.

Conclusions—

Together, these data demonstrate that MMP-2 plays a pivotal role in oxLDL-induced activation of the sphingomyelin/ceramide signaling pathway and subsequent SMC proliferation. These pathways may constitute a potential therapeutic target for modulating the oxLDL-induced proliferation of SMCs in atherosclerosis or restenosis.
Randomized Trial of Atorvastatin for Reduction of Myocardial Damage During Coronary Intervention
Authors: Pasceri Vincenzo , Patti Giuseppe , Nusca Annunziata , Pristipino Christian , Richichi Giuseppe , Di Sciascio Germano
Published: July 2004

Background—

Small myocardial infarctions after percutaneous coronary intervention have been associated with higher risk of cardiac events during follow-up. Observational studies have suggested that statins may lower the risk of procedural myocardial injury. The aim of our study was to confirm this hypothesis in a randomized study.

Methods and Results—

One hundred fifty-three patients with chronic stable angina without previous statin treatment were enrolled in the study. Patients scheduled for elective coronary intervention were randomized to atorvastatin (40 mg/d, n=76) or placebo (n=77) 7 days before the procedure. Creatine kinase-MB, troponin I, and myoglobin levels were measured at baseline and at 8 and 24 hours after the procedure. Detection of markers of myocardial injury above the upper normal limit was significantly lower in the statin group versus the placebo group: 12% versus 35% for creatine kinase-MB (
P
=0.001), 20% versus 48% for troponin I (
P
=0.0004), and 22% versus 51% for myoglobin (
P
=0.0005). Myocardial infarction by creatine kinase-MB determination was detected after coronary intervention in 5% of patients in the statin group and in 18% of those in the placebo group (
P
=0.025). Postprocedural peak levels of creatine kinase-MB (2.9±3 versus 7.5±18 ng/mL,
P
=0.007), troponin I (0.09±0.2 versus 0.47±1.3 ng/mL,
P
=0.0008), and myoglobin (58±36 versus 81±49 ng/mL,
P
=0.0002) were also significantly lower in the statin than in the placebo group.

Conclusions—

Pretreatment with atorvastatin 40 mg/d for 7 days significantly reduces procedural myocardial injury in elective coronary intervention. These results may influence practice patterns with regard to adjuvant pharmacological therapy before percutaneous revascularization.
Effect of Aldosterone Antagonism on Myocardial Dysfunction in Hypertensive Patients With Diastolic Heart Failure
Authors: Mottram Philip M. , Haluska Brian , Leano Rodel , Cowley Diane , Stowasser Michael , Marwick Thomas H.
Published: July 2004

Background—

Specific treatments targeting the pathophysiology of hypertensive heart disease are lacking. As aldosterone has been implicated in the genesis of myocardial fibrosis, hypertrophy, and dysfunction, we sought to determine the effects of aldosterone antagonism on myocardial function in hypertensive patients with suspected diastolic heart failure by using sensitive quantitative echocardiographic techniques in a randomized, double-blinded, placebo-controlled study.

Methods and Results—

Thirty medically treated ambulatory hypertensive patients (19 women, age 62±6 years) with exertional dyspnea, ejection fraction >50%, and diastolic dysfunction (E/A <1, E deceleration time >250m/sec) and without ischemia were randomized to spironolactone 25 mg/d or placebo for 6 months. Patients were overweight (31±5 kg/m
2
) with reduced treadmill exercise capacity (6.7±2.1 METS). Long-axis strain rate (SR), peak systolic strain, and cyclic variation of integrated backscatter (CVIB) were averaged from 6 walls in 3 standard apical views. Mean 24-hour ambulatory blood pressure at baseline (133±17/80±7mm Hg) did not change in either group. Values for SR, peak systolic strain, and CVIB were similar between groups at baseline and remained unchanged with placebo. Spironolactone therapy was associated with increases in SR (baseline: −1.57±0.46 s
−1
versus 6-months: −1.91±0.36 s
−1
,
P
<0.01), peak systolic strain (−20.3±5.0% versus −26.9±4.3%,
P
<0.001), and CVIB (7.4±1.7dB versus 8.6±1.7 dB,
P
=0.08). Each parameter was significantly greater in the spironolactone group compared with placebo at 6 months (
P
=0.05,
P
=0.02, and
P
=0.02, respectively), and the increases remained significant after adjusting for baseline differences. The increase in strain was independent of changes in blood pressure with intervention. The spironolactone group also exhibited reduction in posterior wall thickness (
P
=0.04) and a trend to reduced left atrial area (
P
=0.09).

Conclusions—

Aldosterone antagonism improves myocardial function in hypertensive heart disease.
Vascular Endothelial Growth Factor Activation of Sterol Regulatory Element Binding Protein
Authors: Zhou Rui-Hai , Yao Min , Lee Tzong-Shyuan , Zhu Yi , Martins-Green Manuela , Shyy John Y.-J.
Published: July 2004

By stimulating the migration and proliferation of endothelial cells (ECs), vascular endothelial growth factor (VEGF) is a potent angiogenic factor. However, the molecular mechanism involved in the VEGF-induced angiogenesis remains elusive. We hypothesized that sterol regulatory element binding proteins (SREBPs), transcription factors governing cellular lipid homeostasis, play an important role in regulating angiogenesis in response to VEGF. VEGF activated SREBP1 and SREBP2 in ECs, as demonstrated by the increased SREBPs, their cleavage products, and the upregulation of the targeted genes. VEGF-induced SREBP activation depended on SREBP cleavage-activating protein (SCAP), because knocking down SCAP by RNA interference (RNAi) inhibited SREBP activation in response to VEGF. SREBP activation was also blocked by 25-hydroxycholesterol (25-HC). To verify the functional implication of SREBPs in VEGF-induced angiogenesis, we tested the role of SREBPs in EC migration and proliferation. SCAP RNAi or 25-HC inhibited VEGF-induced pseudopodia extension and migration of ECs. Both treatments inhibited VEGF-induced EC proliferation, with cell growth arrested at the G
0
/G
1
phase and a concomitant decrease of the S phase. Blocking the PI3K-Akt pathway inhibited the VEGF-activated SREBPs, demonstrating that PI3K-Akt regulates SREBPs. Consistent with our in vitro data, SREBP1 was detected in newly developed microvasculatures in a rabbit skin partial-thickness wound-healing model. SREBP inhibition also markedly suppressed VEGF-induced angiogenesis in chick embryos. In summary, this study identifies SREBPs as the key molecules in regulating angiogenesis in response to VEGF.
Requirement for Rac1-Dependent NADPH Oxidase in the Cardiovascular and Dipsogenic Actions of Angiotensin II in the Brain
Authors: Zimmerman Matthew C. , Dunlay Ryan P. , Lazartigues Eric , Zhang Yulong , Sharma Ram V. , Engelhardt John F. , Davisson Robin L.
Published: July 2004

We have shown that intracellular superoxide (O
2
·−
) production in CNS neurons plays a key role in the pressor, bradycardic, and dipsogenic actions of Ang II in the brain. In this study, we tested the hypothesis that a Rac1-dependent NADPH oxidase is a key source of O
2
·−
in Ang II–sensitive neurons and is involved in these central Ang II–dependent effects. We performed both in vitro and in vivo studies using adenoviral (Ad)-mediated expression of dominant-negative Rac1 (AdN17Rac1) to inhibit Ang II–stimulated Rac1 activation, an obligatory step in NADPH oxidase activation. Ang II induced a time-dependent increase in Rac1 activation and O
2
·−
production in Neuro-2A cells, and this was abolished by pretreatment with AdN17Rac1 or the NADPH oxidase inhibitors apocynin or diphenylene iodonium. AdN17Rac1 also inhibited Ang II–induced increases in NADPH oxidase activity in primary neurons cultured from central cardiovascular control regions. In contrast, overexpression of wild-type Rac1 (AdwtRac1) caused more robust NADPH oxidase-dependent O
2
·−
production to Ang II. To extend the in vitro studies, the pressor, bradycardic, and drinking responses to intracerebroventricularly (ICV) injected Ang II were measured in mice that had undergone gene transfer of AdN17Rac1 or AdwtRac1 to the brain. AdN17Rac1 abolished the increase in blood pressure, decrease in heart rate, and drinking response induced by ICV injection of Ang II, whereas AdwtRac1 enhanced these physiological effects. The exaggerated physiological responses in AdwtRac1-treated mice were abolished by O
2
·−
scavenging. These results, for the first time, identify a Rac1-dependent NADPH oxidase as the source of central Ang II–induced O
2
·−
production, and implicate this oxidase in cardiovascular diseases associated with dysregulation of brain Ang II signaling, including hypertension.
Systemic Inflammatory Response Depends on Initial Stroke Severity but Is Attenuated by Successful Thrombolysis
Authors: Audebert Heinrich J. , Rott Michaela M. , Eck Thomas , Haberl Roman L.
Published: July 2004

Background and Purpose—

To determine whether body temperature, c-reactive protein (CRP), and white blood cell (WBC) count within the first days after stroke onset correlate with infarct size and stroke severity, and to examine whether successful thrombolysis reduces poststroke inflammation.

Methods—

Out of 1500 consecutive acute ischemic stroke patients, 346 cases (43 patients with thrombolysis) were selected according to the following criteria: admission to hospital ≤24 hours after event, absence of prestroke and poststroke infectious disease, no intracerebral hemorrhage or brain stem stroke, and data availability. Body temperature, WBC within 3 days, and CRP within 5 days of event were determined daily. Lesion volume was measured by planimetry on computed tomography or MRI scans. Successful thrombolysis was defined as improvement on the National Institutes of Health Stroke Scale of ≥4 points within 24 hours.

Results—

Increase of inflammatory parameters correlated significantly with lesion volume and stroke severity. This was shown for body temperature on days 2 and 3 (
P
<0.001), CRP on days 1 to 5 (
P
<0.05), and WBC on days 1 to 3 (
P
<0.01). Patients with successful thrombolysis had reduced body temperature on day 3, WBC on days 2 and 3, and CRP on days 3 to 5 (
P
<0.05).

Conclusions—

Patients with a larger stroke volume and more severe stroke deficits have higher body temperature, CRP, and WBC count in the acute phase after stroke. Successful thrombolysis is related to a significantly attenuated inflammatory response.
Day of the Week and Ischemic Stroke
Authors: Jakovljević Dimitrije
Published: July 2004

Background and Purpose—

The study aim was to examine the incidence of ischemic stroke (IS) by day of the week and its relationship with age, sex, and socioeconomic status (SES).

Methods—

A total of 12 801 IS events in men and women aged 25 to 99 years was recorded in a population-based stroke register (FINMONICA), which was functioning in Finland from 1982 to 1992. We analyzed the weekly variation in IS incidence by pooling the data and stratifying by sex and age. Taxable income and level of education were used as indicators of SES.

Results—

We observed a significant weekly variation in IS occurrence, but the analysis by age group demonstrated a difference by weekday only in the age group 60 to 74, both in men and women (
P
<0.001 and
P
=0.02, respectively). The increase in the number of IS events from Sunday to Monday was pronounced in men (29.2% increase from Sunday to Monday). When stratifying by age, Monday excess in IS incidence was associated with lower SES among persons >59 years of age. No Monday excess was observed in persons with high SES.

Conclusions—

Because the incidence of IS is much higher in persons with low SES than in those with high SES, the Monday excess in persons with low SES is of substantial public health interest. This finding may suggest reasons for the higher IS incidence in persons with low socioeconomic positions and open up some possibilities for prevention.
Individual Patient Data Meta-Analysis of Randomized Controlled Trials of Community Occupational Therapy for Stroke Patients
Authors: Walker M.F. , Leonardi-Bee J. , Bath P. , Langhorne P. , Dewey M. , Corr S. , Drummond A. , Gilbertson L. , Gladman J.R.F. , Jongbloed L. , Logan P. , Parker C.
Published: July 2004

Background and Purpose—

Trials of occupational therapy for stroke patients living in the community have varied in their findings. It is unclear why these discrepancies have occurred.

Methods—

Trials were identified from searches of the Cochrane Library and other sources. The primary outcome measure was the Nottingham Extended Activities of Daily Living (NEADL) score at the end of intervention. Secondary outcome measures included the Barthel Index or the Rivermead ADL (Personal ADL), General Health Questionnaire (GHQ), Nottingham Leisure Questionnaire (NLQ), and death. Data were analyzed using linear or logistic regression with a random effect for trial and adjustment for age, gender, baseline dependency, and method of follow-up. Subgroup analyses compared any occupational therapy intervention with control.

Results—

We included 8 single-blind randomized controlled trials incorporating 1143 patients. Occupational therapy was associated with higher NEADL scores at the end of intervention (weighted mean difference [WMD], 1.30 points, 95% confidence intervals [CI], 0.47 to 2.13) and higher leisure scores at the end of intervention (WMD, 1.51 points; 95% CI, 0.24 to 2.79). Occupational therapy emphasizing activities of daily living (ADL) was associated with improved end of intervention NEADL (WMD, 1.61 points; 95% CI, 0.72 to 2.49) and personal activities of daily living (odds ratio [OR], 0.65; 95% CI, 0.46 to 0.91), but not NLQ. Leisure-based occupational therapy improved end of intervention NLQ (WMD, 1.96 points; 95% CI, 0.27 to 3.66) but not NEADL or PADL.

Conclusions—

Community occupational therapy significantly improved personal and extended activities of daily living and leisure activity in patients with stroke. Better outcomes were found with targeted interventions.
Late Measures of Brain Injury After Neonatal Hypoxia–Ischemia in Mice
Authors: Ten Vadim S. , Wu Ed X. , Tang Haiying , Bradley-Moore Maria , Fedarau Maksim V. , Ratner Veniamin I. , Stark Raymond I. , Gingrich Jay A. , Pinsky David J.
Published: July 2004

Background and Purpose—

This work was undertaken to determine to what degree long-term neurofunctional outcome of neonatal hypoxic–ischemic (HI) brain injury in mice correlates with anatomical extent of cerebral damage assessed by magnetic resonance imaging (MRI) and histopathology.

Methods—

On postnatal day 7, mice were subjected to HI. At 7 to 9 weeks after HI neurofunctional outcome was assessed by water-maze, rota-rod, and open-field test performance, followed by cerebral MRI and histopathology evaluation.

Results—

At 10 weeks after HI, MRI revealed ipsilateral brain atrophy alone or with porencephalic cyst formation and contralateral ventriculomegaly. Adult HI-affected mice, especially those that developed a porencephalic cyst, demonstrated significant neurofunctional deficit compared with age-matched naïve mice. HI-affected mice with ipsilateral cerebral atrophy but without porencephaly demonstrated no or an intermediate level of neurofunctional deficit. Neurobehavioral assessment of mice subjected to HI insult revealed a strong correlation between degree of brain injury and functional neurohandicap.

Conclusions—

This is the first study to demonstrate that long-term neurofunctional outcome in mice after a neonatal HI correlates tightly with anatomical pattern/extent of cerebral damage, defined by MRI and histopathology.
Are There Time-Dependent Differences in Diffusion and Perfusion Within the First 6 Hours After Stroke Onset?
Authors: Fiehler Jens , Kucinski Thomas , Knudsen Karina , Rosenkranz Michael , Thomalla Götz , Weiller Cornelius , Röther Joachim , Zeumer Hermann
Published: July 2004

Background and Purpose—

Stroke heterogeneity in computed tomography-based studies has been attributed as main cause for missing efficacy of intravenous tissue plasminogen activator (tPA) therapy within 3 to 6 hours. We investigated early time-dependent differences in acute stroke pathophysiology by multiparametric magnetic resonance imaging (MRI).

Methods—

Stroke MRI of 112 acute ischemic stroke patients within <6 hours were dichotomized into a <3-hour group (n=52) and a 3- to 6-hour group (n=60). Infarct volume was determined on days 5 to 8. Lesion volumes were determined for apparent diffusion coefficient (ADC_man) and the subregion with ADC values <550×10
−9
mm/s
2
(ADC <550), and for the time-to-peak (TTP) delay of 2 to 4 seconds, 4 to 6 seconds, 6 to 8 seconds, and >8 seconds. A subsample analysis was performed for occlusions of the middle carotid artery (MCA) trunk (n=36) and MCA branches (n=30), and for all patients treated by intravenous tPA (n=70).

Results—

ADC and TTP lesion volumes were not different within <3 hours compared with volumes at 3 to 6 hours. In patients receiving intravenous tPA (n=70), there were no significant differences in ADC_man, TTP >2 seconds, and infarct volume (days 5 to 8) between the 2 groups. There was a greater proportion of ADC <550/ADC_man, which was most pronounced in patients with MCA trunk occlusions after 3 to 6 hours and a larger mismatch in the <3-hour group compared with that of the 3- to 6-hour group. In MCA branch occlusions, there was a less severe TTP delay after 3 to 6 hours. However, all differences missed the significance level (
P
=0.05) after correction for multiple testing.

Conclusions—

We observed no significant time-dependent differences within 6 hours after stroke onset in degree and volume of diffusion and perfusion impairment. An exclusion from intravenous tPA solely based on a rigid 3-hour time window seems unjustified in MRI-confirmed ischemic stroke.
Cardiac Autonomic Derangement and Arrhythmias in Right-Sided Stroke With Insular Involvement
Authors: Colivicchi Furio , Bassi Andrea , Santini Massimo , Caltagirone Carlo
Published: July 2004

Background and Purpose—

The insula of the right cerebral hemisphere may have a major role in cardiac autonomic control. This study was aimed at assessing the effects of acute right insular ischemic damage on heart rate variability (HRV) and arrhythmias.

Methods—

Holter monitoring for 24 hours was performed in 103 consecutive patients with first-ever acute ischemic stroke. Time and frequency domain measures of HRV and arrhythmias were considered in all cases.

Results—

Forty-nine patients (47.5%) had a right-sided infarction, whereas 54 (52.5%) had a left-sided infarction. Insular involvement was present in 33 patients with right-sided stroke (67.3%) and in 36 patients with left-sided stroke (66.6%). When compared with all other stroke patients, subjects with right-sided insular damage showed significantly lower values of the standard deviation of all normal-to-normal (SDNN) R wave to R wave (RR) intervals and of the root mean square of differences (rMSSD) of adjacent normal-to-normal RR intervals, and higher low-frequency/high-frequency ratio values (
P
<0.05). Right insular stroke was also associated with more complex arrhythmias than any other localization (
P
<0.05). Moreover, in the whole population of stroke patients, lower values of SDNN were associated with the presence of more frequent and complex arrhythmias.

Conclusions—

These findings further support the notion that the right insula is implicated in the autonomic control of cardiac activity and that acute right insular damage may lead to a derangement of cardiac function with potential prognostic implications.
Gene expression profiling of normal and malignant CD34-derived megakaryocytic cells
Authors: Tenedini Elena , Fagioli Maria Elena , Vianelli Nicola , Tazzari Pier Luigi , Ricci Francesca , Tagliafico Enrico , Ricci Paolo , Gugliotta Luigi , Martinelli Giovanni , Tura Sante , Baccarani Michele , Ferrari Sergio , Catani Lucia
Published: July 2004

Gene expression profiles of bone marrow (BM) CD34-derived megakaryocytic cells (MKs) were compared in patients with essential thrombocythemia (ET) and healthy subjects using oligonucleotide microarray analysis to identify differentially expressed genes and disease-specific transcripts. We found that proapoptotic genes such as BAX, BNIP3, and BNIP3L were down-regulated in ET MKs together with genes that are components of the mitochondrial permeability transition pore complex, a system with a pivotal role in apoptosis. Conversely, antiapoptotic genes such as IGF1-R and CFLAR were up-regulated in the malignant cells, as was the SDF1 gene, which favors cell survival. On the basis of the array results, we characterized apoptosis of normal and ET MKs by time-course evaluation of annexin-V and sub-G1 peak DNA stainings of immature and mature MKs after culture in serum-free medium with an optimal thrombopoietin concentration, and annexin-V–positive MKs only, with decreasing thrombopoietin concentrations. ET MKs were more resistant to apoptosis than their normal counterparts. We conclude that imbalance between proliferation and apoptosis seems to be an important step in malignant ET megakaryocytopoiesis.
Human immunodeficiency virus–driven expansion of CD4+CD25+ regulatory T cells, which suppress HIV-specific CD4 T-cell responses in HIV-infected patients
Authors: Weiss Laurence , Donkova-Petrini Vladimira , Caccavelli Laure , Balbo Michèle , Carbonneil Cédric , Levy Yves
Published: July 2004

The present study demonstrates that CD4+CD25+ T cells, expanded in peripheral blood of HIV-infected patients receiving highly active antiretroviral therapy (HAART), exhibit phenotypic, molecular, and functional characteristics of regulatory T cells. The majority of peripheral CD4+CD25+ T cells from HIV-infected patients expressed a memory phenotype. They were found to constitutively express transcription factor forkhead box P3 (Foxp3) messengers. CD4+CD25+ T cells weakly proliferated to immobilized anti-CD3 monoclonal antibody (mAb) and addition of soluble anti-CD28 mAb significantly increased proliferation. In contrast to CD4+CD25– T cells, CD4+CD25+ T cells from HIV-infected patients did not proliferate in response to recall antigens and to p24 protein. The proliferative capacity of CD4 T cells to tuberculin, cytomegalovirus (CMV), and p24 significantly increased following depletion of CD4+CD25+ T cells. Furthermore, addition of increasing numbers of CD4+CD25+ T cells resulted in a dose-dependent inhibition of CD4+CD25– T-cell proliferation to tuberculin and p24. CD4+CD25+ T cells responded specifically to p24 antigen stimulation by expressing transforming growth factor β (TGF-β) and interleukin 10 (IL-10), thus indicating the presence of p24-specific CD4+ T cells among the CD4+CD25+ T-cell subset. Suppressive activity was not dependent on the secretion of TGF-β or IL-10. Taken together, our results suggest that persistence of HIV antigens might trigger the expansion of CD4+CD25+ regulatory T cells, which might induce a tolerance to HIV in vivo.
Interleukin-2-induced survival of natural killer (NK) cells involving phosphatidylinositol-3 kinase-dependent reduction of ceramide through acid sphingomyelinase, sphingomyelin synthase, and glucosylceramide synthase
Authors: Taguchi Yoshimitsu , Kondo Tadakazu , Watanabe Mitsumasa , Miyaji Michihiko , Umehara Hisanori , Kozutsumi Yasunori , Okazaki Toshiro
Published: July 2004

Interleukin 2 (IL-2) rescued human natural killer (NK) KHYG-1 cells from apoptosis along with a reduction of ceramide. Conversely, an increase of ceramide inhibited IL-2-rescued survival. IL-2 deprivation-induced activation of acid sphingomyelinase (SMase) and inhibition of glucosylceramide synthase (GCS) and sphingomyelin synthase (SMS) were normalized by IL-2 supplementation. A phosphatidyl inositol-3 (PI-3) kinase inhibitor, LY294002, inhibited IL-2-rescued survival, but a mitogen-activated protein kinase inhibitor, PD98059, and an inhibitor of Janus tyrosine kinase/signal transducer and activator of transcription pathway, AG490, did not. LY294002 inhibited IL-2-induced reduction of ceramide through activation of acid SMase and inhibition of GCS and SMS, suggesting the positive involvement of PI-3 kinase in ceramide reduction through enzymatic regulation. Indeed, a constitutively active PI-3 kinase enhanced growth rate and ceramide reduction through inhibition of acid SMase and activation of GCS and SMS. Further, LY294002 inhibited IL-2-induced changes of transcriptional level as well as mRNA and protein levels in acid SMase and GCS but did not affect the stability of the mRNAs. These results suggest that PI-3 kinase-dependent reduction of ceramide through regulation of acid SMase, GCS, and SMS plays a role in IL-2-rescued survival of NK cells. (Blood. 2004;104:3285-3293)
Identification of a novel natural regulatory CD8 T-cell subset and analysis of its mechanism of regulation
Authors: Xystrakis Emmanuel , Dejean Anne S. , Bernard Isabelle , Druet Philippe , Liblau Roland , Gonzalez-Dunia Daniel , Saoudi Abdelhadi
Published: July 2004

The immune system contains natural regulatory T cells that control the magnitude of the immune response during physiologic and pathologic conditions. Although this suppressive function was historically attributed to CD8 T cells, most recent reports have focused on natural regulatory CD4 T cells. In the present study, we describe a new subset of natural CD8 regulatory T cells in normal healthy animals. This subset expresses low levels of CD45RC at its surface (CD45RClow); produces mainly interleukin-4 (IL-4), IL-10, and IL-13 cytokines upon in vitro stimulation; expresses Foxp3 and cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4); and is not cytotoxic against allogeneic targets. This subset suppresses the proliferation and differentiation of autologous CD4 T cells into type-1 cytokines producing T cells after stimulation with allogeneic accessory cells. We also provide evidence that this regulatory subset mediates its suppression by cell-to-cell contact and not through secretion of suppressive cytokines. Finally, the regulatory activity of CD8 CD45RClow cells is also demonstrated in vivo in a rat model of CD4-dependent graft-versus-host disease. Collectively, these data demonstrate for the first time that freshly isolated rat CD8 CD45RClow T cells contain T cells with regulatory properties, a result that enlarges the general picture of T-cell-mediated regulation. (Blood. 2004;104:3294-3301)
Visualization of lymphatic vessels through NF-κB activity
Authors: Saban Marcia R. , Mémet Sylvie , Jackson David G. , Ash John , Roig Aurelio A. , Israël Alain , Saban Ricardo
Published: July 2004

The molecular biology of lymphatics is only rudimentary owing to the long-standing absence of specific markers, and scanty is the information regarding bladder lymphatic vessels. By using mice with a reporter gene for nuclear factor κB (NF-κB) activity (κB-lacZ) in combination with immunohistochemical staining with a specific lymphatic marker (LYVE-1), we show, for the first time, that NF-κB is constitutively active in lymphatic endothelium in the urinary bladder, uterus, intestine, heart, and airways. Tie2-lacZ mice confirmed that the structures observed in κB-lacZ mice were not blood vessels. In addition, acute instillation of lipopolysaccharide (LPS) or tumor necrosis factor α (TNF-α) into the κB-lacZ mouse bladder revealed the capacity of this transgenic in reporting inducible NF-κB activity. Our findings demonstrate an overriding constitutive NF-κB activity in the lymphatic system. They also provide a working model for detecting lymphatic vessels and evoke testable hypotheses regarding the role of lymphatic vessels in health and disease.
The transcriptionally active form of AML1 is required for hematopoietic rescue of the AML1-deficient embryonic para-aortic splanchnopleural (P-Sp) region
Authors: Goyama Susumu , Yamaguchi Yuko , Imai Yoichi , Kawazu Masahito , Nakagawa Masahiro , Asai Takashi , Kumano Keiki , Mitani Kinuko , Ogawa Seishi , Chiba Shigeru , Kurokawa Mineo , Hirai Hisamaru
Published: July 2004

Acute myelogenous leukemia 1 (AML1; runt-related transcription factor 1 [Runx1]) is a member of Runx transcription factors and is essential for definitive hematopoiesis. Although AML1 possesses several subdomains of defined biochemical functions, the physiologic relevance of each subdomain to hematopoietic development has been poorly understood. Recently, the consequence of carboxy-terminal truncation in AML1 was analyzed by the hematopoietic rescue assay of AML1-deficient mouse embryonic stem cells using the gene knock-in approach. Nonetheless, a role for specific internal domains, as well as for mutations found in a human disease, of AML1 remains to be elucidated. In this study, we established an experimental system to efficiently evaluate the hematopoietic potential of AML1 using a coculture system of the murine embryonic para-aortic splanchnopleural (P-Sp) region with a stromal cell line, OP9. In this system, the hematopoietic defect of AML1-deficient P-Sp can be rescued by expressing AML1 with retroviral infection. By analysis of AML1 mutants, we demonstrated that the hematopoietic potential of AML1 was closely related to its transcriptional activity. Furthermore, we showed that other Runx transcription factors, Runx2/AML3 or Runx3/AML2, could rescue the hematopoietic defect of AML1-deficient P-Sp. Thus, this experimental system will become a valuable tool to analyze the physiologic function and domain contribution of Runx proteins in hematopoiesis.
NADPH oxidase mediates vascular endothelial cadherin phosphorylation and endothelial dysfunction
Authors: Nwariaku Fiemu E. , Liu Zijuan , Zhu Xudong , Nahari Dorit , Ingle Christine , Wu Ru Feng , Gu Ying , Sarosi George , Terada Lance S.
Published: July 2004

Vascular endothelial activation is an early step during leukocyte/endothelial adhesion and transendothelial leukocyte migration in inflammatory states. Leukocyte transmigration occurs through intercellular gaps between endothelial cells. Vascular endothelial cadherin (VE-cadherin) is a predominant component of endothelial adherens junctions that regulates intercellular gap formation. We found that tumor necrosis factor (TNF) caused tyrosine phosphorylation of VE-cadherin, separation of lateral cell-cell junctions, and intercellular gap formation in human umbilical vein endothelial cell (HUVEC) monolayers. These events appear to be regulated by intracellular oxidant production through endothelial NAD(P)H (nicotinamide adenine dinucleotide phosphate) oxidase because antioxidants and expression of a transdominant inhibitor of the NADPH oxidase, p67(V204A), effectively blocked the effects of TNF on all 3 parameters of junctional integrity. Antioxidants and p67(V204A) also decreased TNF-induced JNK activation. Dominant-negative JNK abrogated VE-cadherin phosphorylation and junctional separation, suggesting a downstream role for JNK. Finally, adenoviral delivery of the kinase dead PAK1(K298A) decreased TNF-induced JNK activation, VE-cadherin phosphorylation, and lateral junctional separation, consistent with the proposed involvement of PAK1 upstream of the NADPH oxidase. Thus, PAK-1 acts in concert with oxidase during TNF-induced oxidant production and loss of endothelial cell junctional integrity.
Significant receptor affinities of metabolites and a degradation product of mometasone furoate
Authors: Valotis Anagnostis , Högger Petra
Published: July 2004

Mometasone furoate (MF) is a highly potent glucocorticoid used topically to treat inflammation in the lung, nose and on the skin. However, so far no information has been published on the human glucocorticoid receptor activity of the metabolites or degradation products of MF. We have now determined the relative receptor binding affinities of the known metabolite 6β-OH MF and the degradation product 9,11-epoxy MF to understand their possible contribution to undesirable systemic side effects. In competition experiments with human lung glucocorticoid receptors we have determined the relative receptor affinities (RRA) of these substances with reference to dexamethasone (RRA = 100). We have discovered that 6β-OH MF and 9,11-epoxy MF display RRAs of 206 ± 15 and 220 ± 22, respectively. This level of activity is similar to that of the clinically used inhaled corticosteroid flunisolide (RRA 180 ± 11). Furthermore we observed that 9,11-epoxy MF is a chemically reactive metabolite. In recovery experiments with human plasma and lung tissue we found a time dependent decrease in extractability of the compound. Hence, we provide data that might contribute to the understanding of the pharmacokinetics as well as the clinical effects of MF.
Attentional influences on functional mapping of speech sounds in human auditory cortex
Authors: Obleser Jonas , Elbert Thomas , Eulitz Carsten
Published: July 2004

Background

The speech signal contains both information about phonological features such as place of articulation and non-phonological features such as speaker identity. These are different aspects of the 'what'-processing stream (speaker vs. speech content), and here we show that they can be further segregated as they may occur in parallel but within different neural substrates. Subjects listened to two different vowels, each spoken by two different speakers. During one block, they were asked to identify a given vowel irrespectively of the speaker (phonological categorization), while during the other block the speaker had to be identified irrespectively of the vowel (speaker categorization). Auditory evoked fields were recorded using 148-channel magnetoencephalography (MEG), and magnetic source imaging was obtained for 17 subjects.

Results

During phonological categorization, a vowel-dependent difference of N100m source location perpendicular to the main tonotopic gradient replicated previous findings. In speaker categorization, the relative mapping of vowels remained unchanged but sources were shifted towards more posterior and more superior locations.

Conclusions

These results imply that the N100m reflects the extraction of abstract invariants from the speech signal. This part of the processing is accomplished in auditory areas anterior to AI, which are part of the auditory 'what' system. This network seems to include spatially separable modules for identifying the phonological information and for associating it with a particular speaker that are activated in synchrony but within different regions, suggesting that the 'what' processing can be more adequately modeled by a stream of parallel stages. The relative activation of the parallel processing stages can be modulated by attentional or task demands.
A quantitative analysis of qualitative studies in clinical journals for the 2000 publishing year
Authors: McKibbon Kathleen Ann , Gadd Cynthia S
Published: July 2004

Background

Quantitative studies are becoming more recognized as important to understanding health care with all of its richness and complexities. The purpose of this descriptive survey was to provide a quantitative evaluation of the qualitative studies published in 170 core clinical journals for 2000.

Methods

All identified studies that used qualitative methods were reviewed to ascertain which clinical journals publish qualitative studies and to extract research methods, content (persons and health care issues studied), and whether mixed methods (quantitative and qualitative methods) were used.

Results

60 330 articles were reviewed. 355 reports of original qualitative studies and 12 systematic review articles were identified in 48 journals. Most of the journals were in the discipline of nursing. Only 4 of the most highly cited health care journals, based on ISI Science Citation Index (SCI) Impact Factors, published qualitative studies. 37 of the 355 original reports used both qualitative and quantitative (mixed) methods. Patients and non-health care settings were the most common groups of people studied. Diseases and conditions were cancer, mental health, pregnancy and childbirth, and cerebrovascular disease with many other diseases and conditions represented. Phenomenology and grounded theory were commonly used; substantial ethnography was also present. No substantial differences were noted for content or methods when articles published in all disciplines were compared with articles published in nursing titles or when studies with mixed methods were compared with studies that included only qualitative methods.

Conclusions

The clinical literature includes many qualitative studies although they are often published in nursing journals or journals with low SCI Impact Factor journals. Many qualitative studies incorporate both qualitative and quantitative methods.
World health system performance revisited: the impact of varying the relative importance of health system goals
Authors: Lauer Jeremy A , Lovell CA Knox , Murray Christopher JL , Evans David B
Published: July 2004

Background

In 2002, the World Health Organization published a health system performance ranking for 191 member countries. The ranking was based on five indicators, with fixed weights common to all countries.

Methods

We investigate the feasibility and desirability of using mathematical programming techniques that allow weights to vary across countries to reflect their varying circumstances and objectives.

Results

By global distributional measures, scores and ranks are found to be not very sensitive to changes in weights, although differences can be large for individual countries.

Conclusions

Building the flexibility of variable weights into calculation of the performance index is a useful way to respond to the debates and criticisms appearing since publication of the ranking.
An active electrode for biopotential recording from small localized bio-sources
Authors: Valchinov Emil S , Pallikarakis Nicolas E
Published: July 2004

Background

Laser bio-stimulation is a well-established procedure in Medical Acupuncture. Nevertheless there is still a confusion as to whether it works or the effect is just placebo. Although a plethora of scientific papers published, showing positive clinical results, there is still a lack of objective scientific proofs about the bio-stimulation effect of lasers used in Acupuncture. The objective of this work was to design and build a body surface electrode and an amplifier for biopotential recording from acupuncture points, considered here as small localized bio-sources (SLB). The design is aimed for studying SLB potentials provoked by laser stimulus, in search for objective proofs of the bio-stimulation effect of lasers used in Medical Acupuncture.

Methods

The active electrode presented features a new adjustable anchoring system and fractionation of the biopotential amplifier between the electrode and the cabinet's location. The new adjustable electrode anchoring system is designed to reduce the electrode-skin contact impedance, its variation and motion artifacts. That is achieved by increasing the electrode-skin tension and decreasing its relative movement. Additionally the sensing element provides local constant skin stretching thus eliminating the contribution of the skin potential artifact. The electrode is attached to the skin by a double-sided adhesive pad, where the sensing element is a stainless steel, 4 mm in diameter. The fractionation of the biopotential amplifier is done by incorporating the amplifier's front-end op-amps at the electrodes, thus avoiding the use of extra buffers. The biopotential amplifier features two selectable modes of operation: semi-AC-mode with a -3 dB bandwidth of 0.32–1000 Hz and AC-mode with a bandwidth of 0.16–1000 Hz.

Results

The average measured DC electrode-skin contact impedance of the proposed electrode was 450 kΩ, with electrode tension of 0.3 kg/cm2 on an unprepared skin of the inner forearm. The peak-to-peak noise voltage measured at the amplifier output, with input terminals connected to common, was 10 mVp-p, or 2 μVp-p referred to the input. The common-mode rejection ratio of the amplifier was 96 dB at 50 Hz, measured with imbalanced electrodes' impedances. The prototype was also tested practically and sample records were obtained after a low intensity SLB laser stimulation. All measurements showed almost a complete absence of 50 Hz interference, although no electrolyte gel or skin preparation was applied.

Conclusion

The results showed that the new active electrode presented significantly reduced the electrode-skin impedance, its variation and motion artifact influences. This allowed SLB signals with relatively high quality to be recorded without skin preparation. The design offers low noise and major reduction in parts, size and power consumption. The active electrode specifications were found to be better or at least comparable to those of other existing designs.
Proposed methods for reviewing the outcomes of health research: the impact of funding by the UK's 'Arthritis Research Campaign'
Authors: Hanney Stephen R , Grant Jonathan , Wooding Steven , Buxton Martin J
Published: July 2004

Background

External and internal factors are increasingly encouraging research funding bodies to demonstrate the outcomes of their research. Traditional methods of assessing research are still important, but can be merged into broader multi-dimensional categorisations of research benefits. The onus has hitherto been on public sector funding bodies, but in the UK the role of medical charities in funding research is particularly important and the Arthritis Research Campaign, the leading medical charity in its field in the UK, commissioned a study to identify the outcomes from research that it funds. This article describes the methods to be used.

Methods

A case study approach will enable narratives to be told, illuminating how research funded in the early 1990s was (or was not) translated into practice. Each study will be organised using a common structure, which, with careful selection of cases, should enable cross-case analysis to illustrate the strengths of different modes and categories of research. Three main interdependent methods will be used: documentary and literature review; semi-structured interviews; and bibliometric analysis. The evaluative framework for organising the studies was previously used for assessing the benefits from health services research. Here, it has been specifically amended for a medical charity that funds a wide range of research and is concerned to develop the careers of researchers. It was further refined in three pilot studies. The framework has two main elements. First, a multi-dimensional categorisation of benefits going from the knowledge produced in peer reviewed journal articles through to the health and potential economic gain. The second element is a logic model, which, with various stages, should provide a way of organising the studies. The stock of knowledge is important: much research, especially basic, will feed into it and influence further research rather than directly lead to health gains. The cross-case analysis will look for factors associated with outcomes.

Conclusions

The pilots confirmed the applicability of the methods for a full study which should assist the Arthritis Research Campaign to demonstrate the outcomes from its funding, and provide it with evidence to inform its own policies.
Neural networks as effective techniques in clinical management of patients: some case studies
Authors: Martín José D. , Soria Emilio , Camps Gustavo , Serrano Antonio J. , Sepúlveda José R. , Jiménez Víctor
Published: July 2004

In this paper, we present four examples of effective implementation of neural systems in the daily clinical practice. There are two main goals in this work; the first one is to show that neural networks are especially well-suited tools for solving different kind of medical/pharmaceutical problems, given the complex input output relationships and the few a priori knowledge about data distribution and variable relations. The second goal is to develop specific software applications, which enclose complex mathematical models, to clinicians; thus, the use of such models as decision support systems is facilitated. Four important pharmaceutical problems are considered in this study: identification of patients with potential risk of postchemotherapy emesis, classification of patients depending on their risk of digoxin intoxication, prediction of cyclosporine A through concentration and prediction of erythropoietin blood concentrations. The Multilayer Perceptron in classification problems and dynamic neural networks, such as the Elman recurrent neural network and the Finite Impulse Response neural network in prediction problems, have been used. Moreover, network ensembles of different kind of networks have been taken into account. Results show that neural networks are suitable tools for medical classification and prediction tasks, outperforming the mostly used methods in these problems (logistic regression and multivariate analysis).
Agent architecture for smart adaptive systems
Authors: Lhotska Lenka , Stepankova Olga
Published: July 2004

This paper discusses the possibility of utilizing a multiagent system as a platform for development of a smart adaptive system in medicine. A knowledge-based model of the agents’ mutual awareness (social knowledge) is presented. The tri-base acquaintance (3bA) model formalizing the agent’s social behaviour knowledge and co-operation neighbourhood knowledge is enhanced to support attention focussing and to ensure a holistic complex perception of the problem. The paper focuses on an analysis of the content of 3bA knowledge bases for applications in medical decision support. An architecture for a multiagent system, ADAM, for medical decision support and monitoring is proposed.