bluuebunny/crossref_metadata_2025 huggingface dataset:
Exercise Capacity and the Risk of Death in Women
Authors: Gulati Martha , Pandey Dilip K. , Arnsdorf Morton F. , Lauderdale Diane S. , Thisted Ronald A. , Wicklund Roxanne H. , Al-Hani Arfan J. , Black Henry R.
Published: September 2003

Background—

Cardiovascular disease is the leading cause of death among women and accounts for more than half of their deaths. Women have been underrepresented in most studies of cardiovascular disease. Reduced physical fitness has been shown to increase the risk of death in men. Exercise capacity measured by exercise stress test is an objective measure of physical fitness. The hypothesis that reduced exercise capacity is associated with an increased risk of death was investigated in a cohort of 5721 asymptomatic women who underwent baseline examinations in 1992.

Methods and Results—

Information collected at baseline included medical and family history, demographic characteristics, physical examination, and symptom-limited stress ECG, using the Bruce protocol. Exercise capacity was measured in metabolic equivalents (MET). Nonfasting blood was analyzed at baseline. A National Death Index search was performed to identify all-cause death and date of death up to the end of 2000. The mean age of participants at baseline was 52±11 years. Framingham Risk Score–adjusted hazards ratios (with 95% CI) of death associated with MET levels of <5, 5 to 8, and >8 were 3.1 (2.0 to 4.7), 1.9 (1.3 to 2.9), and 1.00, respectively. The Framingham Risk Score–adjusted mortality risk decreased by 17% for every 1-MET increase.

Conclusions—

This is the largest cohort of asymptomatic women studied in this context over the longest period of follow-up. This study confirms that exercise capacity is an independent predictor of death in asymptomatic women, greater than what has been previously established among men. The implications for clinical practice and health care policy are far reaching.
Determinants of Elevated Pulse Pressure in Middle-Aged and Older Subjects With Uncomplicated Systolic Hypertension
Authors: Mitchell Gary F. , Lacourcière Yves , Ouellet Jean-Pascal , Izzo Joseph L. , Neutel Joel , Kerwin Linda J. , Block Alan J. , Pfeffer Marc A.
Published: September 2003

Background—

Elevated pulse pressure (PP) is associated with increased cardiovascular risk and is thought to be secondary to elastin fragmentation with secondary collagen deposition and stiffening of the aortic wall, leading to a dilated, noncompliant vasculature.

Methods and Results—

By use of calibrated tonometry and pulsed Doppler, arterial stiffness and pulsatile hemodynamics were assessed in 128 subjects with uncomplicated systolic hypertension (supine systolic pressure ≥140 mm Hg off medication) and 30 normotensive control subjects of comparable age and gender. Pulse-wave velocity was assessed from tonometry and body surface measurements. Characteristic impedance (Z
c
) was calculated from the ratio of change in carotid pressure and aortic flow in early systole. Effective aortic diameter was assessed by use of the water hammer equation. Hypertensives were heavier (
P
<0.001) and had higher PP (
P
<0.001), which was attributable primarily to higher Z
c
(
P
<0.001), especially in women. Pulse-wave velocity was higher in hypertensives (
P
=0.001); however, this difference was not significant after adjustment for differences in mean arterial pressure (MAP) (
P
>0.153), whereas increased Z
c
remained highly significant (
P
<0.001). Increased Z
c
in women and in hypertensive men was attributable to decreased effective aortic diameter, with no difference in wall stiffness at comparable MAP and body weight.

Conclusions—

Elevated PP in systolic hypertension was independent of MAP and was attributable primarily to elevated Z
c
and reduced effective diameter of the proximal aorta. These findings are not consistent with the hypothesis of secondary aortic degeneration, dilation, and wall stiffening but rather suggest that aortic function may play an active role in the pathophysiology of systolic hypertension.
Angiotensin II–NAD(P)H Oxidase–Stimulated Superoxide Modifies Tubulovascular Nitric Oxide Cross-Talk in Renal Outer Medulla
Authors: Mori Takefumi , Cowley Allen W.
Published: September 2003

The source of superoxide (O
2
·−) production and cell-to-cell interactions of O
2
·− and nitric oxide (NO) in response to angiotensin II (AngII) were studied by fluorescence microscopic techniques to image rat renal outer medullary microtissue strips. Changes in intracellular O
2
·− were determined by dihydroethidium-ethidium ratios, and NO was determined with 4,5-diaminofluorescein diacetate. AngII (1 μmol/L) significantly increased O
2
·− in the isolated, medullary thick ascending limb (mTAL). These responses were inhibited by the superoxide dismutase mimetic 4-hydroxytetramethylpiperidine-1-oxyl (TEMPOL) and by the NAD(P)H oxidase inhibitors diphenylene iodonium and apocynin. AngII did not increase O
2
·− in either pericytes of isolated, intact vasa recta (VR) or pericytes of VR with a disrupted endothelium, even when surrounded by mTAL. However, AngII did increase O
2
·− when the tissue strips were preincubated with the NO scavenger 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (carboxy-PTIO), indicating that cross-talk of O
2
·− from mTAL to the VR occurred but was normally inhibited by NO. Also, tissue O
2
·− reduction by TEMPOL increased the diffusion of NO from mTAL to the pericytes, indicating that cross-talk of NO from the mTAL to the VR is also inhibited by O
2
·−. We conclude that AngII stimulates O
2
·− production in mTAL via the NAD(P)H oxidase pathway and that interactions of O
2
·− and NO ultimately determine the effectiveness of in situ free-radical cross-talk between the mTAL and the VR.
In Salt-Sensitive Hypertension, Increased Superoxide Production Is Linked to Functional Upregulation of Angiotensin II
Authors: Zhou Ming-Sheng , Adam Ahmed G. , Jaimes Edgar A. , Raij Leopoldo
Published: September 2003

The balance between endothelial nitric oxide (NO) and angiotensin II (Ang II) maintains the homeostasis of the cardiovascular and renal systems. We tested the hypothesis that increased oxidant stress linked to a functional imbalance between NO and Ang II might play a central pathogenetic role in salt-sensitive (SS) hypertension. We studied Dahl SS (DS) rats during the prehypertensive (5 days) and hypertensive (12 weeks) phases of a high-salt (4% NaCl) diet. Control rats received a normal-salt (0.5% NaCl, [NS]) diet. Prehypertensive DS rats (systolic blood pressure [SBP] 138±2 mm Hg) manifested a 35% increase (
P
<0.05) in aortic superoxide (O
2
−
) production without evidence of end-organ damage. Hypertensive DS rats (SBP 214±11 mm Hg) had impaired endothelium-dependent relaxation (EDR) and increased aortic O
2
−
production (320%), urinary isoprostane excretion (83%), aortic (20%) and left ventricular (LVH, 21%) hypertrophy, and proteinuria (124%). In prehypertensive DS rats, candesartan (10 mg · kg
−1
· d
−1
) an Ang II type 1 receptor blocker (ARB), normalized O
2
−
production. In hypertensive DS rats, the ARB decreased aortic O
2
−
production by 71% and normalized EDR without affecting SBP (212±8 mm Hg), aortic hypertrophy, LVH, or proteinuria. Switching hypertensive DS rats to an NS diet did not affect SBP (208±8 mm Hg), LVH, aortic hypertrophy, or proteinuria and had minimal effects on O
2
−
and EDR. Concomitant ARB administration plus a switch to an NS diet normalized SBP (138±8 mm Hg) as well as end-organ damage. Dahl salt-resistant rats fed an HS diet for 12 weeks did not show hypertension or increased O
2
−
production. Thus, SS hypertension might represent a specific vascular diathesis linked to functional upregulation of Ang II action (increased O
2
−
synthesis) accompanied by insufficient NO bioavailability, which promotes severe endothelial dysfunction.
Influence of Weight Reduction on Blood Pressure
Authors: Neter Judith E. , Stam Bianca E. , Kok Frans J. , Grobbee Diederick E. , Geleijnse Johanna M.
Published: September 2003

Increased body weight is a strong risk factor for hypertension. A meta-analysis of randomized controlled trials was performed to estimate the effect of weight reduction on blood pressure overall and in population subgroups. Twenty-five randomized, controlled trials (comprising 34 strata) published between 1966 and 2002 with a total of 4874 participants were included. A random-effects model was used to account for heterogeneity among trials. A net weight reduction of −5.1 kg (95% confidence interval [CI], −6.03 to −4.25) by means of energy restriction, increased physical activity, or both reduced systolic blood pressure by −4.44 mm Hg (95% CI, −5.93 to −2.95) and diastolic blood pressure by −3.57 mm Hg (95% CI, −4.88 to −2.25). Blood pressure reductions were −1.05 mm Hg (95% CI, −1.43 to −0.66) systolic and −0.92 mm Hg (95% CI, −1.28 to −0.55) diastolic when expressed per kilogram of weight loss. As expected, significantly larger blood pressure reductions were observed in populations with an average weight loss >5 kg than in populations with less weight loss, both for systolic (−6.63 mm Hg [95% CI, −8.43 to −4.82] vs −2.70 mm Hg [95% CI, −4.59 to −0.81]) and diastolic (−5.12 mm Hg [95% CI, −6.48 to −3.75] vs −2.01 mm Hg [95% CI, −3.47 to −0.54]) blood pressure. The effect on diastolic blood pressure was significantly larger in populations taking antihypertensive drugs than in untreated populations (−5.31 mm Hg [95% CI, −6.64 to −3.99] vs −2.91 mm Hg [95% CI, −3.66 to −2.16]). This meta-analysis clearly shows that weight loss is important for the prevention and treatment of hypertension.
Arterial Endothelium-Specific Activin Receptor-Like Kinase 1 Expression Suggests Its Role in Arterialization and Vascular Remodeling
Authors: Seki Tsugio , Yun Jihye , Oh S. Paul
Published: September 2003

Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant vascular disorder characterized by epistaxis, mucocutaneous telangiectases, and arteriovenous malformations (AVM). Two genes are linked to HHT: endoglin (
ENG
) in HHT1 and activin receptor-like kinase 1 (
ACVRL1
;
ALK1
) in HHT2. Although both genes are involved in the transforming growth factor β signaling pathways, the pathogenetic mechanisms for HHT remain elusive. It was shown that mutations in the
Alk1
gene in mice and zebrafish resulted in an embryonic lethal phenotype due to severe dilation of blood vessels. We created a novel null mutant mouse line for
Alk1
(
Alk1
lacZ
) by replacing its exons, including the one that encodes the transmembrane domain, with the β-galactosidase gene. Using
Alk1

lacZ

mice, we show that Alk1 is predominantly expressed in developing arterial endothelium. Alk1 expression is greatly diminished in adult arteries, but is induced in preexisting feeding arteries and newly forming arterial vessels during wound healing and tumor angiogenesis. We also show that hemodynamic changes, which require vascular remodeling, may regulate Alk1 expression. Our studies suggest the role of Alk1 signaling in arterialization and remodeling of arteries. Contrary to the current view of HHT as venous disease, our findings suggest that the arterioles rather than the venules are the primary vessels affected by the loss of an
Alk1
allele, and that blood vessels with reduction in Alk1 expression may harbor defects in responding to demands for vascular remodeling.
Analysis of Mean Transit Time of Contrast Medium in Ruptured and Unruptured Arteriovenous Malformations
Authors: Todaka Tatemi , Hamada Jun-ichiro , Kai Yutaka , Morioka Motohiro , Ushio Yukitaka
Published: September 2003

Background and Purpose—

To clarify hemodynamic risk factors for hemorrhage in arteriovenous malformations (AVMs), the mean transit time (MTT) of feeding arteries and draining veins in AVMs with and without hemorrhage was measured and analyzed.

Methods—

Morphological features such as the number and diameter of draining and feeding vessels and the AVM nidus volume were evaluated in 30 patients with supratentorial AVMs. The MTT of feeding arteries and draining veins was measured with the use of time-density curves obtained by digital subtraction angiography. The correlation between hemorrhage and morphology and hemorrhage and MTT was analyzed statistically.

Results—

The nidus volume was not significantly different between hemorrhagic and nonhemorrhagic AVMs. However, between ruptured and unruptured AVMs there was a significant difference in the mean number of draining veins (1.5±0.69 versus 2.3±0.50;
P
=0.006), the MTT of the feeding artery (1.10±0.24 versus 1.62±0.55;
P
=0.03), and the ratio of the MTT of the draining to the feeding vessels (1.71±0.43 versus 1.05±0.07;
P
<0.001).

Conclusions—

A high ratio of the MTT of draining veins to feeding arteries suggests disequilibrium between nidal inflow and outflow. The consequent increased pressure in the draining vein may contribute to the development of AVM hemorrhage.
Protein Z in Ischemic Stroke and its Etiologic Subtypes
Authors: McQuillan Andrew M. , Eikelboom John W. , Hankey Graeme J. , Baker Ross , Thom Jim , Staton Janelle , Yi Qilong , Cole Vanessa
Published: September 2003

Background and Purpose—

Protein Z is a vitamin K–dependent plasma protein whose significance in arterial thrombosis remains uncertain. The objectives of this study were to determine the association between protein Z, ischemic stroke, and etiologic subtypes of ischemic stroke.

Methods—

We conducted a case-control study of 173 hospital cases of first-ever ischemic stroke and 186 randomly selected community controls. Using established criteria, we classified cases of stroke by etiologic subtype. Protein Z concentrations were measured during the first 7 days and at 3 to 6 months after the acute stroke event.

Results—

Blood levels of protein Z measured within 7 days of acute stroke were significantly higher in cases than in controls (geometric mean, 1.46 versus 1.16 μg/mL;
P
<0.0001). Compared with the lowest tertile, the upper 2 tertiles of protein Z were associated with an adjusted odds ratio (OR) of ischemic stroke of 1.75 (95% CI, 1.00 to 3.07) for the second tertile and 3.07 (95% CI, 1.73 to 5.45) for the upper tertile. The adjusted odds of ischemic stroke caused by large-artery atherothrombosis was nearly 8-fold greater for those with protein Z concentrations in the upper tertile compared with the lower tertile (OR, 7.91; 95% CI, 3.11 to 20.14). The adjusted odds of ischemic stroke due to small-artery disease (OR, 1.79; 95% CI, 0.83 to 3.87) and cardioembolism (OR, 1.80; 95% CI, 0.58 to 5.64) was also increased among individuals with protein Z concentrations in the upper tertile compared with the lower tertile, but not significantly so. There was no significant difference between mean protein Z concentrations among cases in the convalescent phase (3 months) after stroke and age- and sex-matched controls.

Conclusions—

There is a strong, independent relationship between elevated blood levels of protein Z and ischemic stroke during the acute phase, particularly ischemic stroke due to large-artery atherothromboembolism, which is no longer evident during the convalescent phase. These results are consistent with the notion that protein Z is either an important factor in the pathogenesis of ischemic stroke due to large-artery atherothromboembolism or an acute phase reactant. Further studies are required to elucidate whether protein Z has a causative or prognostic role in acute arterial thrombosis.
McDonald's as a Disneyized Institution
Authors: Bryman Alan
Published: September 2003

This article addresses the process of Disneyization as a parallel process to that of McDonaldization and raises the question of whether McDonald's restaurants can themselves be regarded as Disneyized as well as McDonaldized. It is suggested that McDonald's restaurants fit the notion of Disneyization well in that there is growing use of theming in outlets, the company offers a wide range of merchandising opportunities, McDonald's involves itself with other spheres of consumption so that there is dedifferentiation of consumption, and its staff are supposed to exhibit emotional labor. Some of the implications of the discussion for issues to do with globalization are discussed.
Global Habitus, Local Stratification, and Symbolic Struggles Over Identity
Authors: Illouz Eva , John Nicholas
Published: September 2003

Employing Bourdieu's concepts of field and habitus, this article argues that McDonaldization, and by extension globalization, is a social and cultural practice, implemented by actors, with intentions, motivations, and goals. This analytical approach accomplishes two important objectives: first, it moves away from an agentless view of globalization, viewing it instead as a social practice demanding forms of skills and strategies used by actors, and second, this approach helps us understand how forms of global capital enable and are enabled by local forms of social stratification and identity. The research is based on content analysis of newspaper articles on McDonald's in Israel and an in-depth interview with the chief executive officer of McDonald's Israel. It focuses on his social trajectory, asking how his ethnic, class, and political affiliations within the Israeli context endowed him with a global habitus. This global habitus is apparent in the liberal outlook defended by the McDonald's chairman, an outlook that has pitted him against the ultra-orthodox establishment.
Reduced stem cell mobilization in mice receiving antibiotic modulation of the intestinal flora: involvement of endotoxins as cofactors in mobilization
Authors: Velders Gerjo A. , van Os Ronald , Hagoort Henny , Verzaal Perry , Guiot Henri F. L. , Lindley Ivan J. D. , Willemze Roel , Opdenakker Ghislain , Fibbe Willem E.
Published: September 2003

Since endotoxins are potent inducers of stem cell mobilization, we hypothesized that their presence in the gut may play a role in cytokine-induced mobilization. To address this possibility we added ciprofloxacin and polymyxin B to the drinking water of Balb/c mice mobilized with either interleukin-8 (IL-8), granulocyte colony-stimulating factor (G-CSF), or flt3 ligand (FL). The yield of colony-forming units (CFUs) was significantly reduced in all mice treated with these antibiotics when compared with controls (IL-8: 192 ± 61 vs 290 ± 64, P < .05; G-CSF: 1925 ± 1216 vs 3371 ± 1214, P < .05; FL: 562 ± 213 vs 1068 ± 528, P < .05). Treatment with ciprofloxacin eliminated only aerobic Gramnegative bacteria from the feces without effect on mobilization. Polymyxin B treatment did not result in decontamination but significantly reduced the number of mobilized hematopoietic progenitor cells (HPCs) most likely due to the endotoxin binding capacity of polymyxin B. More than 90% of the gastrointestinal flora consists of anaerobic bacteria. Elimination of the anaerobic flora by metronidazol led to a significantly reduced number of mobilized HPCs when compared with controls (IL-8: 55 ± 66 vs 538 ± 216, P < .05). Germ-free OF1 mice showed a significantly reduced mobilization compared with their wild-type controls (IL-8 controls: 378 ± 182, IL-8 germ free: 157 ± 53, P < .05). Finally, we performed reconstitution experiments adding Escherichia coli–derived endotoxins to the drinking water of decontaminated mice. This resulted in partial restoration of the IL-8–induced mobilization (67 ± 28 vs 190 ± 98.1, P <.01). Our results indicate that endotoxins serve as cofactors in cytokine-induced mobilization. Modification of the endotoxin content by antibiotic treatment may affect the yield of cytokine-induced mobilization.
Ultrastructural study shows morphologic features of apoptosis and para-apoptosis in megakaryocytes from patients with idiopathic thrombocytopenic purpura
Authors: Houwerzijl Ewout J. , Blom Nel R. , van der Want Johannes J. L. , Esselink Mariet T. , Koornstra Jan J. , Smit Jan W. , Louwes Henk , Vellenga Edo , de Wolf Joost Th. M.
Published: September 2003

To investigate whether altered megakaryocyte morphology contributes to reduced platelet production in idiopathic thrombocytopenic purpura (ITP), ultrastructural analysis of megakaryocytes was performed in 11 ITP patients. Ultrastructural abnormalities compatible with (para-)apoptosis were present in 78% ± 14% of ITP megakaryocytes, which could be reversed by in vivo treatment with prednisone and intravenous immunoglobulin. Immunohistochemistry of bone marrow biopsies of ITP patients with extensive apoptosis showed an increased number of megakaryocytes with activated caspase-3 compared with normal (28% ± 4% versus 0%). No difference, however, was observed in the number of bone marrow megakaryocyte colony-forming units (ITP, 118 ± 93/105 bone marrow cells; versus controls, 128 ± 101/105 bone marrow cells; P = .7). To demonstrate that circulating antibodies might affect megakaryocytes, suspension cultures of CD34+ cells were performed with ITP or normal plasma. Morphology compatible with (para-)apoptosis could be induced in cultured megakaryocytes with ITP plasma (2 of 10 samples positive for antiplatelet autoantibodies). Finally, the plasma glycocalicin index, a parameter of platelet and megakaryocyte destruction, was increased in ITP (57 ± 70 versus 0.7 ± 0.2; P = .009) and correlated with the proportion of megakaryocytes showing (para-) apoptotic ultrastructure (P = .02; r = 0.7). In conclusion, most ITP megakaryocytes show ultrastructural features of (para-) apoptosis, probably due to action of factors present in ITP plasma.
Interleukin-6–dependent gene expression profiles in multiple myeloma INA-6 cells reveal a Bcl-2 family–independent survival pathway closely associated with Stat3 activation
Authors: Brocke-Heidrich Katja , Kretzschmar Antje K. , Pfeifer Gabriele , Henze Christian , Löffler Dennis , Koczan Dirk , Thiesen Hans-Jürgen , Burger Renate , Gramatzki Martin , Horn Friedemann
Published: September 2003

Interleukin 6 (IL-6) is a growth and survival factor for multiple myeloma cells. As we report here, the IL-6–dependent human myeloma cell line INA-6 responds with a remarkably rapid and complete apoptosis to cytokine withdrawal. Among the antiapoptotic members of the B-cell lymphoma-2 (Bcl-2) family of apoptosis regulators, only myeloid cell factor-1 (Mcl-1) was slightly induced by IL-6. Overexpression studies demonstrated, however, that IL-6 does not exert its survival effect primarily through this pathway. The IL-6 signal transduction pathways required for survival and the target genes controlled by them were analyzed by using mutated receptor chimeras. The activation of signal transducer and activator of transcription 3 (Stat3) turned out to be obligatory for the survival of INA-6 cells. The same held true for survival and growth of XG-1 myeloma cells. Gene expression profiling of INA-6 cells by using oligonucleotide microarrays revealed many novel IL-6 target genes, among them several genes coding for transcriptional regulators involved in B-lymphocyte differentiation as well as for growth factors and receptors potentially implicated in autocrine or paracrine growth control. Regulation of most IL-6 target genes required the activation of Stat3, underscoring its central role for IL-6 signal transduction. Taken together, our data provide evidence for the existence of an as yet unknown Stat3-dependent survival pathway in myeloma cells.
Hepatic injury after nonmyeloablative conditioning followed by allogeneic hematopoietic cell transplantation: a study of 193 patients
Authors: Hogan William J. , Maris Michael , Storer Barry , Sandmaier Brenda M. , Maloney David G. , Schoch H. Gary , Woolfrey Ann E. , Shulman Howard M. , Storb Rainer , McDonald George B.
Published: September 2003

Liver injury is a frequent, serious complication of allogeneic hematopoietic cell transplantation (HCT) following myeloablative preparative regimens. We sought to determine the frequency and severity of hepatic injury after nonmyeloablative conditioning and its relationship to outcomes. One hundred ninety-three consecutive patients who received 2 Gy total body irradiation with or without fludarabine were evaluated for end points related to liver injury. Patients with diseases treatable by HCT who were ineligible for conventional myeloablative allogeneic HCT because of advanced age and/or comorbid conditions were included. Fifty-one patients (26%) developed hyperbilirubinemia of 68.4 μM (4 mg/dL) or greater, most commonly resulting from cholestasis due to graft-versus-host disease (GVHD) or sepsis. Pretransplantation factors associated with liver dysfunction were a diagnosis of aggressive malignancy (hazard ratio [HR] 1.9; P = .04) and the inclusion of fludarabine in the conditioning regimen (HR 1.8; P = .07). Overall survival at 1 year was superior for patients who had maximal serum bilirubin levels in the normal (78%) or minimally elevated (22.23-66.69 μM [1.3-3.9 mg/dL]) ranges (69%) compared with those in the 68.4 to 117.99 μM (4-6.9 mg/dL; 20%), 119.7 to 169.29 μM (7.0-9.9 mg/dL; 17%), and 171.0 μM (10 mg/dL; 19%) or greater groups. In summary, significant jaundice occurred in 26% of patients and was predominantly due to cholestasis resulting from GVHD and/or sepsis. Aggressive malignancies (mainly advanced disease) and later development of jaundice after transplantation predicted inferior survival.
Prognostic significance of bcl-xL gene expression and apoptotic cell counts in follicular lymphoma
Authors: Zhao Wei-Li , Daneshpouy Marjan Ertault , Mounier Nicolas , Brière Josette , Leboeuf Christophe , Plassa Louis-François , Turpin Elisabeth , Cayuela Jean-Michel , Ameisen Jean-Claude , Gisselbrecht Christian , Janin Anne
Published: September 2003

bcl-xL, a member of the Bcl-2 family, exerts an antiapoptotic effect on lymphocytes. To assess its clinical significance in patients with follicular lymphoma, realtime quantitative reverse transcription–polymerase chain reaction (RT-PCR) analysis of bcl-xL gene expression was investigated in whole lymph node sections and laser-microdissected lymphoma cells of 27 patients. Compared with 10 patients with reactive follicular hyperplasia, the bcl-xL gene was overexpressed in patients with follicular lymphoma at a higher level in microdissected lymphoma cells. The bcl-xL gene level correlated with the number of apoptotic lymphoma cells labeled by terminal deoxytransferase-catalyzed DNA nick-end labeling (TUNEL) assays (r = -0.7736). Clinically, a high bcl-xL level was significantly associated with multiple sites of extranodal involvement (P = .0020), elevated lactate dehydrogenase level (P = .0478), and an International Prognostic Index indicating high risk (P = .0235). Moreover, bcl-xL gene overexpression was linked to short overall survival times (P = .0129). The value of bcl-xL gene expression as a prognostic marker in follicular lymphoma should thus be considered.
Adult human hematopoietic cells provide functional hemangioblast activity
Authors: Cogle Christopher R. , Wainman David A. , Jorgensen Marda L. , Guthrie Steven M. , Mames Robert N. , Scott Edward W.
Published: September 2003

The murine adult hematopoietic stem cell is able to function as a hemangioblast, contributing both to blood reconstitution and to blood vessel repair in response to ischemic injury. We developed a novel mouse xenotransplantation model of retinal neovascularization to test human hematopoietic cell plasticity. Immunocompromised nonobese diabetic (NOD)/scid mice underwent myeloablative conditioning and transplantation with human CD34+ umbilical cord blood. After multilineage reconstitution was established, retinal ischemia was induced to promote neovascularization. Our results demonstrate human retinal neovascularization, thus revealing the functional hemangioblast activity of human hematopoietic cells.
Effects of prednisone and genetic polymorphisms on etoposide disposition in children with acute lymphoblastic leukemia
Authors: Kishi Shinji , Yang Wenjian , Boureau Benoit , Morand Stanislas , Das Soma , Chen Peixian , Cook Edwin H. , Rosner Gary L. , Schuetz Erin , Pui Ching-Hon , Relling Mary V.
Published: September 2003

Etoposide is a substrate for P-glycoprotein, CYP3A4, CYP3A5, and UGT1A1. Glucocorticoids modulate CYP3A and P-glycoprotein in preclinical models, but their effect on clinical etoposide disposition is unknown. We studied the pharmacokinetics of etoposide and its catechol metabolite in children with acute lymphoblastic leukemia, along with polymorphisms in CYP3A4, CYP3A5, MDR1, GSTP1, UGT1A1, and VDR. Plasma pharmacokinetics were assessed at day 29, after 1 month of prednisone (n = 102), and at week 54, without prednisone (n = 44). On day 29, etoposide clearance was higher (47.4 versus 29.2 mL/min/m2, P < .0001) than at week 54. The day 29 etoposide or catechol area under the curve (AUC) was correlated with neutropenia (P = .027 and P = .0008, respectively). The relationship between genotype and etoposide disposition differed by race and by prednisone use. The MDR1 exon 26 CC genotype predicted higher day 29 etoposide clearance (P = .002) for all patients, and the CYP3A5 AA and GSTP1 AA genotypes predicted lower clearance in blacks (P = .02 and .03, respectively). The UGT1A1 6/6, VDR intron 8 GG, and VDR Fok 1 CC genotypes predicted higher week 54 clearance in blacks (P = .039, .036, and .052, respectively). The UGT1A1 6/6 genotype predicted lower catechol AUC. Prednisone strongly induces etoposide clearance, genetic polymorphisms may predict the constitutive and induced clearance of etoposide, and the relationship between genotype and phenotype differs by race.
TRAIL regulates normal erythroid maturation through an ERK-dependent pathway
Authors: Secchiero Paola , Melloni Elisabetta , Heikinheimo Markku , Mannisto Susanna , Di Pietro Roberta , Iacone Antonio , Zauli Giorgio
Published: September 2003

In order to investigate the biologic activity of tumor necrosis factor–related apoptosis-inducing ligand (TRAIL) on human erythropoiesis, glycophorin A (GPA)+ erythroid cells were generated in serum-free liquid phase from human cord blood (CB) CD34+ progenitor cells. The surface expression of TRAIL-R1 was weakly detectable in the early-intermediate phase of erythroid differentiation (days 4-6; dim-intermediate GPA expression), whereas a clear-cut expression of TRAIL-R2 was observed through the entire course of erythroid differentiation (up to days 12-14; bright GPA expression). On the other hand, surface TRAIL-R3 and -R4 were not detected at any culture time. Besides inducing a rapid but small increase of apoptotic cell death, which was abrogated by the pan-caspase inhibitor z-VAD-fmk, the addition of recombinant TRAIL at day 6 of culture inhibited the generation of morphologically mature erythroblasts. Among the intracellular pathways investigated, TRAIL significantly stimulated the extracellular signal-regulated kinase 1/2 (ERK1/2) but not the p38/mitogen-activated protein kinase (MAPK) or the c-Jun NH2-terminal kinase (JNK) pathway. Consistently with a key role of ERK1/2 in mediating the negative effects of TRAIL on erythroid maturation, PD98059, a pharmacologic inhibitor of the ERK pathway, but not z-VAD-fmk or SB203580, a pharmacologic inhibitor of p38/MAPK, reverted the antidifferentiative effect of TRAIL on CB-derived erythroblasts.
Human CD8+ T cells recognize epitopes of the 28-kDa hemolysin and the 38-kDa antigen ofMycobacterium tuberculosis
Authors: Shams Homayoun , Barnes Peter F , Weis Stephen E , Klucar Peter , Wizel Benjamin
Published: September 2003

Mycobacterium tuberculosis antigens that are recognized by human CD8+ T cells are potentially important vaccine target molecules. We used a motif-based strategy to screen selected proteins of M. tuberculosis for peptides predicted to bind to human leukocyte antigen (HLA)-A*0201. We identified two 10 amino acid peptides that elicited cytolytic T lymphocyte activity and interferon-γ production by CD8+ T cells from HLA-A*0201+ healthy tuberculin reactors. These peptides were derived from the 38-kDa antigen and the 28-kDa hemolysin, the latter being a novel target for CD8+ T cells. We speculate that hemolysins may alter the phagosomal membrane surrounding intracellular M. tuberculosis, allowing themselves and other antigens to gain access to the major histocompatibility complex class I processing pathway.
A novel population of Gr-1+-activated macrophages induced during acute toxoplasmosis
Authors: Mordue Dana G , Sibley L David
Published: September 2003

Macrophages are potent mediators of parasite control following in vitro activation, yet the subsets of mononuclear cells that contribute to resistance in vivo remain poorly defined. To identify effector cells that contribute to the control of Toxoplasma gondii during the initial stages of disseminated infection, we developed a low-dose intraperitoneal challenge model. A population of unusual macrophage-like cells was recruited to the peritoneal cavity during the first 4 days postinfection. Surprisingly, these cells expressed the granulocyte marker Gr-1 and the macrophage marker CD68. They also expressed high levels of major histocompatibility complex class II and low levels of F4/80 and CD11b and were negative for the immature myeloid cell marker CD31, the dendritic cell marker CD11c, and the B cell marker B220. Gr-1+ macrophages produced interleukin-12 p40, generated reactive nitrogen intermediates during acute infection, and inhibited virulent type I and nonvirulent type II strains of the parasite in vitro. Gr-1+ macrophages were the primary cell type recruited in response to nonvirulent type II strain parasites, and large numbers of neutrophils (Gr-1+/CD68−) were also recruited to the peritoneum in response to virulent type I strain parasites. Our findings suggest that activated CD68+/Gr-1+ macrophages contribute to parasite control during infection by directly inhibiting parasite replication and through production of T helper cell type I cytokines.
Increased neutrophil influx but no impairment of protective immunity to tuberculosis in mice lacking the CD44 molecule
Authors: Kipnis Andre , Basaraba Randall J , Turner Joanne , Orme Ian M
Published: September 2003

Up-regulation of expression of the cell-surface marker CD44 is a major characteristic of T lymphocytes responding in the lungs of mice infected with Mycobacterium tuberculosis. These lymphocytes express an activated/memory phenotype as seen by their high expression of the CD44 molecule and low expression of CD62L and CD45RB cell-surface molecules. Based on increasing evidence that the CD44 molecule participates in several aspects of the inflammatory response, we evaluated its role in the response to infection with M. tuberculosis using gene-disrupted mice. In this report, we show that CD44 expression is not necessary for the proper trafficking of protective cells to the lungs of mice infected with M. tuberculosis or the direct expression of protective immunity leading to control and containment of the bacterial load in this organ. However, although there were no differences in the bacterial load or migration of activated T lymphocytes to the inflamed lung, the absence of the CD44 molecule resulted in a substantially increased accumulation of neutrophils in the lung. These data indicate that loss of CD44 expression does not alter expression of T helper cell type 1 immunity to tuberculosis in the lungs but has major effects on the overall cellular composition of the immunopathological response.
Collectins and their role in lung immunity
Authors: Hickling T P , Clark H , Malhotra R , Sim R B
Published: September 2003

The collectins are a small family of secreted glycoproteins that contain C-type lectin domains and collagenous regions. They have an important function in innate immunity, recognizing and binding to microorganisms via sugar arrays on the microbial surface. Their function is to enhance adhesion and phaocytosis of microorganisms by agglutination and opsonization. In the lung, two members of the collectin family, surfactant proteins A and D, are major protein constituents of surfactant. Another collectin, mannan-binding lectin, is also present in the upper airways and buccal cavity and may protect against respiratory infections. Recent work has shown that collectins have roles in resistance to allergy and in the control of apoptosis and clearance of apoptotic macrophage in the lung.
Host defense function of the airway epithelium in health and disease: clinical background
Authors: Message Simon D , Johnston Sebastian L
Published: September 2003

Respiratory infection is extremely common and a major cause of morbidity and mortality worldwide. The airway epithelium has an important role in host defense against infection and this is illustrated in this review by considering infection by respiratory viruses. In patients with asthma or chronic obstructive pulmonary disease, respiratory viruses are a common trigger of exacerbations. Rhinoviruses (RV) are the most common virus type detected. Knowledge of the immunopathogenesis of such RV-induced exacerbations remains limited, but information is available from in vitro and from in vivo studies, especially of experimental infection in human volunteers. RV infects and replicates within epithelial cells (EC) of the lower respiratory tract. EC are an important component of the innate-immune response to RV infection. The interaction between virus and the intracellular signaling pathways of the host cell results in activation of potentially antiviral mechanisms, including type 1 interferons and nitric oxide, and in the producton of cytokines and chemokines [interleukin (IL)-1β, IL-6, IL-8, IL-11, IL-16, tumor necrosis factor α, granulocyte macrophage-colony stimulating factor, growth-regulated oncogene-α, epithelial neutrophil-activating protein-78, regulated on activation, normal T expressed and secreted, eotaxin 1/2, macrophage-inflammatory protein-1α], which influence the subsequent induced innate- and specific-immune response. Although this is beneficial in facilitating clearance of virus from the respiratory tract, the generation of proinflammatory mediators and the recruitment of inflammatory cells result in a degree of immunopathology and may amplify pre-existing airway inflammation. Further research will be necessary to determine whether modification of EC responses to respiratory virus infection will be of therapeutic benefit.
Corticotropin-Releasing Hormone (CRH)-Induced Thyrotropin Release Is Directly Mediated through CRH Receptor Type 2 on Thyrotropes
Authors: De Groef Bert , Goris Nesya , Arckens Lutgarde , Kühn Eduard R. , Darras Veerle M.
Published: September 2003

CRH is known as the main stimulator of ACTH release. In representatives of all nonmammalian vertebrates, CRH has also been shown to induce TSH secretion, acting directly at the level of the pituitary. We have investigated which cell types and receptors are involved in CRH-induced TSH release in the chicken (Gallus gallus). Because a lack of CRH type 1 receptors (CRH-R1) on the chicken thyrotropes has been previously reported, two hypotheses were tested using in situ hybridization and perifusion studies: 1) TSH secretion might be induced in a paracrine way involving melanocortins from the corticotropes; and 2) thyrotropes might express another type of CRH-R. For the latter, we have cloned a partial cDNA encoding the chicken CRH-R2. Neither α-melanotropin (α-MSH) nor its powerful analog Nle4,d-Phe7-MSH could mimic the in vitro TSH-releasing effect of ovine CRH. The nonselective melanocortin receptor blocker SHU91199 did not influence CRH- or TRH-induced TSH secretion. On the other hand, we have found that thyrotropes express CRH-R2 mRNA. The involvement of this CRH receptor in the response of thyrotropes to CRH was further confirmed by the fact that TSH release was stimulated by human urocortin III, a CRH-R2-specific agonist, whereas the TSH response to CRH was completely blocked by the CRH-R blocker astressin and the CRH-R2-specific antagonist antisauvagine-30. We conclude that CRH-induced TSH secretion is mediated by CRH-R2 expressed on thyrotropes.
Reduced Intratesticular Testosterone Concentration Alters the Polymerization State of the Sertoli Cell Intermediate Filament Cytoskeleton by Degradation of Vimentin
Authors: Show Matthew D. , Anway Matthew D. , Folmer Janet S. , Zirkin Barry R.
Published: September 2003

The Sertoli cell intermediate filament cytoskeleton is composed of the type III family member vimentin. The distribution of Sertoli cell vimentin varies with the stage of spermatogenesis, with shortening of the filaments at stages VII–VIII, the stages of spermiation. Experimental reduction in intratesticular testosterone (T) concentration also results in the sloughing of advanced spermatids from the Sertoli cells, as well as in the apoptotic death of spermatocytes. We hypothesized that alteration of the distribution of Sertoli cell vimentin might play a role in the loss of germ cells that occurs in response to reduced intratesticular T. To test this hypothesis, intratesticular T was reduced by implanting LH-suppressive SILASTIC brand capsules containing T and estradiol into adult rats for 8 wk. Immunohistochemical analyses revealed that, in response to the implants, the vimentin cytoskeleton collapsed around the Sertoli cell nuclei at all stages of the cycle, losing the extensive branching and structure normally seen at most stages of the cycle. Western blots of isolated Sertoli cells revealed that protein levels did not differ significantly between control and T- and estradiol-treated rats. However, Sertoli cell fractions containing the vimentin monomer revealed that vimentin was cleaved into four to five fragments in Sertoli cells in response to the implants, suggestive of proteolysis. These results indicate that, in response to reduced intratesticular T, the vimentin cytoskeleton of the Sertoli cell collapses to a perinuclear localization, and suggest that this collapse is associated with, and perhaps caused by, the degradation of the vimentin monomer rather than by loss of its expression.
Cyclic ADP-ribose increases Ca2+ removal in smooth muscle
Authors: Bradley Karen N. , Currie Susan , MacMillan Debbi , Muir Thomas C. , McCarron John G.
Published: September 2003

Ca2+ release via ryanodine receptors (RyRs) is vital in cell signalling and regulates diverse activities such as gene expression and excitation-contraction coupling. Cyclic ADP ribose (cADPR), a proposed modulator of RyR activity, releases Ca2+ from the intracellular store in sea urchin eggs but its mechanism of action in other cell types is controversial. In this study, caged cADPR was used to examine the effect of cADPR on Ca2+ signalling in single voltage-clamped smooth muscle cells that have RyR but lack FKBP12.6, a proposed target for cADPR. Although cADPR released Ca2+ in sea urchin eggs (a positive control), it failed to alter global or subsarcolemma [Ca2+]c, to cause Ca2+-induced Ca2+ release or to enhance caffeine responses in colonic myocytes. By contrast, caffeine (an accepted modulator of RyR) was effective in these respects. The lack of cADPR activity on Ca2+ release was unaffected by the introduction of recombinant FKBP12.6 into the myocytes. Indeed in western blots, using brain membrane preparations as a source of FKBP12.6, cADPR did not bind to FKBPs, although FK506 was effective. However, cADPR increased and its antagonist 8-bromo-cADPR slowed the rate of Ca2+ removal from the cytoplasm. The evidence indicates that cADPR modulates [Ca2+]c but not via RyR; the mechanism may involve the sarcolemma Ca2+ pump.
Shear flow-induced motility ofDictyostelium discoideumcells on solid substrate
Authors: Décavé Emmanuel , Rieu Didier , Dalous Jérémie , Fache Sébastien , Bréchet Yves , Fourcade Bertrand , Satre Michel , Bruckert Franz
Published: September 2003

Application of a mild hydrodynamic shear stress to Dicytostelium discoideum cells, unable to detach cells passively from the substrate, triggers a cellular response consisting of steady membrane peeling at the rear edge of the cell and periodic cell contact extensions at its front edge. Both processes require an active actin cytoskeleton. The cell movement induced by the hydrodynamic forces is very similar to amoeboid cell motion during chemotaxis, as for its kinematic parameters and for the involvement of phosphatidylinositol(3,4,5)-trisphosphate internal gradient to maintain cell polarity. Inhibition of phosphoinositide 3-kinases by LY294002 randomizes the orientation of cell movement with respect to the flow without modifying cell speed. Two independent signaling pathways are, therefore, induced in D. discoideum in response to external forces. The first increases the frequency of pseudopodium extension, whereas the second redirects the actin cytoskeleton polymerization machinery to the edge opposite to the stressed side of the cell.
Inhibition of caspase activation and a requirement for NF-κB function in theToxoplasma gondii-mediated blockade of host apoptosis
Authors: Payne T. Matthew , Molestina Robert E. , Sinai Anthony P.
Published: September 2003

Mammalian cells infected with the protozoan parasite Toxoplasma gondii are resistant to many apoptotic stimuli transmitted along both the mitochondrial and death receptor pathways. Apoptosis, and its inhibition in infected cells, was examined using multiple morphological, molecular and biochemical approaches. The data strongly indicate manipulation of the host apoptotic machinery at multiple levels, focusing on the inhibition of host caspases. Activation of the pro-apoptotic caspase family of proteases is a biochemical hallmark of apoptosis. Caspase activation occurs in a highly ordered cascade triggered by the initiator caspases 8 and 9, which activate the executioner caspase, caspase 3. Our findings indicate a profound blockade of caspase activation and activity as the molecular basis for the inhibition of apoptosis in T.-gondii-infected cells. Caspase inhibition was demonstrated using multiple intrinsic and synthetic substrates. Although the specific inhibitory molecule remains to be identified, data indicate an absolute requirement for the host transcription factor NF-κB and, by extension, genes regulated by it. We propose that T. gondii activates the host survival response, thereby increasing the overall resistance of infected cells to apoptotic stimuli.
MEDES: Contact wire wear measuring system used by the Spanish National Railway (RENFE)
Authors: Borromeo S , Aparicio J. L. , Martinez P. M.
Published: September 2003

Measuring systems that detect automatically the degree of wire wear are necessary in order to carry out an efficient infrastructure management and maintenance based on the contact wire condition. An automatic inspection system for overhead wires will be described in this paper. This system has been designed by UPM-DIE (División de Ingeniería Electrónica, Escuela Técnica Superior de Ingenieros Industriales, Universidad Politécnica de Madrid) and funded by RENFE (Spanish National Railway). Currently, the MEDES system is installed and operative in laboratory coaches used by RENFE (Spanish National Railway) and SNCF (French Railway Company). It is based on a computer vision system taking advantage of good reflecting characteristics of the wearing track of the overhead wire. The wearing track is illuminated using laser diodes at 810nm. Charge coupled device (CCD) linear cameras capture the reflected light. A brief contact wire wear measuring systems overview will also be presented.