bluuebunny/crossref_metadata_2025 huggingface dataset:
Estradiol and Progestins Differentially Modulate Leukocyte Infiltration After Vascular Injury
Authors: Xing Dongqi , Miller Andrew , Novak Lea , Rocha Ricardo , Chen Yiu-Fai , Oparil Suzanne
Published: December 2003

Background—

Inflammation plays an important role in the response to endoluminal vascular injury. Estrogen (17β-estradiol, E
2
) inhibits neointima formation in animal models, and the progestin medroxyprogesterone acetate (MPA) blocks this effect. This study tested the hypothesis that E
2
inhibits the migration of inflammatory cells, particularly granulocytes, into the rat carotid arteries after acute endoluminal injury and that MPA blocks this effect.

Methods and Results—

Ovariectomized rats were randomly divided into subgroups and treated with E
2
, MPA, E
2
+MPA, or vehicle and subjected to balloon injury of the right carotid artery. After 1, 3, or 7 days, rats were euthanized, and carotid arteries (injured and control) were analyzed for inflammatory cells by flow cytometry. At 1 day, granulocytes (HIS48
+
and CD45
+
), monocyte/macrophages (Mar1
+
and CD45
+
), and T lymphocytes (CD3
+
and CD45
+
) were increased 26-fold, 12-fold, and 3-fold, respectively, in injured compared with contralateral control arteries of vehicle-treated rats. Granulocytes and monocyte/macrophages decreased markedly by 3 days. E
2
reduced the granulocyte and monocyte/macrophage populations of injured vessels by ≈50% and increased T lymphocytes. MPA had no independent effect on inflammatory cells but completely blocked the effect of E
2
. Immunohistochemical examination verified these findings and localized inflammatory cells to the adventitial and periadventitial domains of injured vessels.

Conclusions—

E
2
may limit the neointimal response to endoluminal vascular injury, at least in part, by limiting leukocyte entry from adventitial/periadventitial tissues into injured vessels early in the injury response.
Targeted Overexpression of Noncleavable and Secreted Forms of Tumor Necrosis Factor Provokes Disparate Cardiac Phenotypes
Authors: Diwan Abhinav , Dibbs Ziad , Nemoto Shintaro , DeFreitas Gilberto , Carabello Blase A. , Sivasubramanian Natarajan , Wilson Eric M. , Spinale Francis G. , Mann Douglas L.
Published: December 2003

Background—

Recent studies suggest that posttranslation processing or “shedding” (ie, secretion) of tumor necrosis factor (TNF) by tumor necrosis factor-α converting enzyme (TACE) may contribute to the left ventricular (LV) remodeling that occurs in the failing human heart.

Methods and Results—

To address the functional significance of TNF shedding, we generated lines of transgenic mice with targeted overexpression of secreted wild-type (MHCsTNF
2
) TNF and overexpression of a mutated noncleavable transmembrane form of TNF (MHCmTNF). Both lines of mice had overlapping levels of myocardial TNF protein; however, the phenotypes of the MHCsTNF2 and MHCmTNF mice were strikingly disparate. Whereas the MHCmTNF mice developed a concentric LV hypertrophy phenotype, the MHCsTNF
2
mice developed a dilated LV phenotype. The fibrillar collagen weave in MHCmTNF mice with concentric hypertrophy was characterized by thick collagen fibrils and increased collagen content, whereas the fibrillar collagen weave in the MHCsTNF
2
mice with LV dilation was characterized by a diminished collagen content. Inhibition of matrix metalloproteinases with a broad-based matrix metalloproteinase inhibitor prevented LV dilation in the MHCsTNF
2
mice.

Conclusions—

These findings suggest that posttranslational processing of TNF, as opposed to TNF expression per se, is responsible for the adverse cardiac remodeling that occurs after sustained TNF overexpression.
Increased Central Artery Stiffness in Impaired Glucose Metabolism and Type 2 Diabetes
Authors: Schram Miranda T. , Henry Ronald M.A , van Dijk Rob A.J.M , Kostense Piet J. , Dekker Jacqueline M. , Nijpels Giel , Heine Robert J. , Bouter Lex M. , Westerhof Nico , Stehouwer Coen D.A.
Published: December 2003

Impaired glucose metabolism (IGM) and type 2 diabetes (DM-2) are associated with high cardiovascular disease risk. Increases in peripheral and central artery stiffness may represent pathophysiologic pathways through which glucose tolerance status leads to cardiovascular disease. Peripheral artery stiffness increases with deteriorating glucose tolerance status, whereas this trend remains unclear for central artery stiffness. Therefore, we investigated the associations between glucose tolerance status and estimates of central arterial stiffness. We performed a population-based study of 619 individuals (normal glucose metabolism, n=261; IGM, n=170; and DM-2, n=188) and assessed central artery stiffness by measuring total systemic arterial compliance, aortic pressure augmentation index, and carotid-femoral transit time. After adjustment for sex, age, heart rate, height, body mass index, and mean arterial pressure, DM-2 was associated with decreased total systemic arterial compliance, increased aortic augmentation index, and decreased carotid-femoral transit time. IGM was borderline significantly associated with decreased total systemic arterial compliance. Respective regression coefficients (95% confidence intervals) for IGM and DM-2 compared with normal glucose metabolism were −0.05 (−0.11 to 0.01) and −0.13 (−0.19 to −0.07) mL/mm Hg for total systemic arterial compliance; 1.1 (−0.2 to 2.5) and 1.6 (0.2 to 3.0) percentage points for aortic augmentation index; and −0.85 (−5.20 to 3.49) and −4.95 (−9.41 to −0.48) ms for carotid-femoral transit time. IGM and DM-2 are associated with increased central artery stiffness, which is more pronounced in DM-2. Deteriorating glucose tolerance is associated with increased central and peripheral arterial stiffness, which may partly explain why both DM-2 and IGM are associated with increased cardiovascular risk.
Ganglionic Action of Angiotensin Contributes to Sympathetic Activity in Renin-Angiotensinogen Transgenic Mice
Authors: Ma Xiuying , Sigmund Curt D. , Hingtgen Shawn D. , Tian Xin , Davisson Robin L. , Abboud Francois M. , Chapleau Mark W.
Published: December 2003

In addition to central nervous system actions, angiotensin (Ang) II may increase sympathetic nerve activity (SNA) via a direct action on sympathetic ganglia. We hypothesized that sympathetic ganglionic actions of endogenous Ang II contribute to SNA in transgenic mice that overexpress renin and angiotensinogen (R
+
A
+
mice). Renal SNA and arterial pressure were recorded in anesthetized R
+
A
+
and littermate control mice before and after ganglionic blockade, and after additional blockade of angiotensin type 1 (AT
1
) receptors with losartan. Ganglionic blockade essentially abolished SNA in control mice, but only reduced SNA to 47±18% of baseline in R
+
A
+
mice. The residual SNA remaining after ganglionic blockade in R
+
A
+
mice was reduced from 47±18% to 8±6% of baseline by losartan (
P
<0.05). The sympathoinhibitory response to losartan was accompanied by an enhanced decrease in arterial pressure in R
+
A
+
mice compared with that observed in control mice. AT
1
receptor expression in sympathetic ganglia, as measured by real-time reverse transcription–polymerase chain reaction, was increased ≈3-fold in R
+
A
+
versus control mice. The results demonstrate that, as anticipated, essentially all of the renal postganglionic SNA in control mice is driven by preganglionic input. The major new finding is that Ang II–evoked ganglionic activity accounts for ≈40% of total SNA in R
+
A
+
mice. The significant contribution of the direct ganglionic action of Ang II in R
+
A
+
mice likely reflects both increased levels of Ang II and upregulation of AT
1
receptors in sympathetic ganglia.
NADH Oxidase Activity of Rat Cardiac Sarcoplasmic Reticulum Regulates Calcium-Induced Calcium Release
Authors: Cherednichenko Gennady , Zima Aleksey V. , Feng Wei , Schaefer Saul , Blatter Lothar A. , Pessah Isaac N.
Published: December 2003

NADH and Ca
2+
have important regulatory functions in cardiomyocytes related to excitation-contraction coupling and ATP production. To elucidate elements of these functions, we examined the effect of NADH on sarcoplasmic reticulum (SR) Ca
2+
release and the mechanisms of this regulation. Physiological concentrations of cytosolic NADH inhibited ryanodine receptor type 2 (RyR2)–mediated Ca
2+
-induced Ca
2+
release (CICR) from SR membranes (IC
50
=120 μmol/L) and significantly lowered single channel open probability. In permeabilized single ventricular cardiomyocytes, NADH significantly inhibited the amplitude and frequency of spontaneous Ca
2+
release. Blockers of electron transport prevented the inhibitory effect of NADH on CICR in isolated membranes and permeabilized cells, as well as on the activity of RyR2 channels reconstituted in lipid bilayer. An endogenous NADH oxidase activity from rat heart copurified with SR enriched with RyR2. A significant contribution by mitochondria was excluded as NADH oxidation by SR exhibited >9-fold higher catalytic activity (8.8 μmol/mg protein per minute) in the absence of exogenous mitochondrial complex I (ubiquinone) or complex III (cytochrome
c
) electron acceptors, but was inhibited by rotenone and pyridaben (IC
50
=2 to 3 nmol/L), antimycin A (IC
50
=13 nmol/L), and diphenyleneiodonium (IC
50
=28 μmol/L). Cardiac junctional SR treated with [
3
H](trifluoromethyl)diazirinyl-pyridaben specifically labeled a single 23-kDa PSST-like protein. These data indicate that NADH oxidation is tightly linked to, and essential for, negative regulation of the RyR2 complex and is a likely component of an important physiological negative-feedback mechanism coupling SR Ca
2+
fluxes and mitochondrial energy production.
α
4
β
1
Integrin Mediates Selective Endothelial Cell Responses to Thrombospondins 1 and 2 In Vitro and Modulates Angiogenesis In Vivo
Authors: Calzada Maria J. , Zhou Longen , Sipes John M. , Zhang Jane , Krutzsch Henry C. , Iruela-Arispe M. Luisa , Annis Douglas S. , Mosher Deane F. , Roberts David D.
Published: December 2003

We examined the function of α
4
β
1
integrin in angiogenesis and in mediating endothelial cell responses to the angiogenesis modulators, thrombospondin-1 and thrombospondin-2. α
4
β
1
supports adhesion of venous endothelial cells but not of microvascular endothelial cells on immobilized thrombospondin-1, vascular cell adhesion molecule-1, or recombinant N-terminal regions of thrombospondin-1 and thrombospondin-2. Chemotactic activities of this region of thrombospondin-1 and thrombospondin-2 are also mediated by α
4
β
1
, whereas antagonism of fibroblast growth factor-2–stimulated chemotaxis is not mediated by this region. Immobilized N-terminal regions of thrombospondin-1 and thrombospondin-2 promote endothelial cell survival and proliferation in an α
4
β
1
-dependent manner. Soluble α
4
β
1
antagonists inhibit angiogenesis in the chick chorioallantoic membrane and neovascularization of mouse muscle explants. The latter inhibition is thrombospondin-1–dependent and not observed in explants from thrombospondin-1
−/−
mice. Antagonizing α
4
β
1
may in part block proangiogenic activities of thrombospondin-1 and thrombospondin-2, because N-terminal regions of thrombospondin-1 and thrombospondin-2 containing the α
4
β
1
binding sequence stimulate angiogenesis in vivo. Therefore, α
4
β
1
is an important endothelial cell receptor for mediating motility and proliferative responses to thrombospondins and for modulation of angiogenesis.
Homocysteine Induces Endothelial Cell Detachment and Vessel Wall Thickening During Chick Embryonic Development
Authors: Boot Marit J. , Steegers-Theunissen Régine P.M. , Poelmann Robert E. , van Iperen Liesbeth , Gittenberger-de Groot Adriana C.
Published: December 2003

Homocysteine affects the migration and differentiation of neural crest cells in vitro and can result in neural tube defects in vivo. Furthermore, homocysteine has been described as an important determinant in vascular disease in human adults. However, little is known about the effects of homocysteine on the development of embryonic vessels. In this study, we injected homocysteine (30 μmol/L) into the neural tube lumen of chick embryos at the time point of neural crest cell emigration, and analyzed the effects on the neural crest–derived pharyngeal arch arteries, like the brachiocephalic arteries, and the mesoderm-derived arteries, such as the dorsal aorta. By stage HH35, we observed detachment of the endothelium, decreased expression of the extracellular matrix proteins fibrillin-2, and fibronectin in the pharyngeal arch arteries, whereas the dorsal aorta was identical in homocysteine-neural tube–injected and control embryos. No effect of homocysteine on endothelin-1 mRNA expression was observed. By stage HH40, the brachiocephalic arteries of homocysteine-neural tube–injected embryos displayed a decreased lumen diameter, an increased intima- and media-thickness, and an increased number of actin layers compared with the brachiocephalic arteries in control embryos. We propose that homocysteine affects the neural crest–derived smooth muscle cells and their extracellular matrix proteins in the pharyngeal arch arteries, resulting in an abnormal smooth muscle to endothelial cell interaction, leading to endothelial cell detachment. We suggest that, as in adult life, increased homocysteine concentrations lead to vascular damage in the embryo. This prenatal damage might increase the susceptibility to develop vessel pathology later in life.
Interleukin-6 Induces Oxidative Stress and Endothelial Dysfunction by Overexpression of the Angiotensin II Type 1 Receptor
Authors: Wassmann Sven , Stumpf Michaela , Strehlow Kerstin , Schmid Andreas , Schieffer Bernhard , Böhm Michael , Nickenig Georg
Published: December 2003

Angiotensin II type 1 (AT
1
) receptor activation as well as proinflammatory cytokines such as interleukin-6 (IL-6) are involved in the development and progression of atherosclerosis. The detailed underlying mechanisms including interactions between inflammatory agonists and the renin-angiotensin system are poorly understood. Stimulation of cultured rat aortic vascular smooth muscle cells (VSMCs) with IL-6 led to upregulation of AT
1
receptor mRNA and protein expression, as assessed by Northern and Western blot experiments. Nuclear run-on and transcription blockade experiments showed that IL-6 increases AT
1
receptor mRNA de novo synthesis but not mRNA stability. Preincubation of VSMCs with IL-6 resulted in an enhanced angiotensin II–induced production of reactive oxygen species, as assessed by DCF fluorescence laser microscopy. Treatment of C57BL/6J mice with IL-6 for 18 days increased vascular AT
1
receptor expression (real-time RT-PCR) and angiotensin II–induced vasoconstriction, enhanced vascular superoxide production (L-012 chemiluminescence, DHE fluorescence), and impaired endothelium-dependent vasodilatation. These effects were completely omitted in AT
1
receptor knockout mice (AT1A
−/−
mice). Upregulation of vascular AT
1
receptor expression in vitro and in vivo is decisively involved in IL-6–induced propagation of oxidative stress and endothelial dysfunction. This interaction of the proinflammatory cytokine IL-6 with the renin-angiotensin system may represent an important pathogenetic mechanism in the atherosclerotic process.
Rapamycin sensitizes multiple myeloma cells to apoptosis induced by dexamethasone
Authors: Strömberg Thomas , Dimberg Anna , Hammarberg Anna , Carlson Kristina , Österborg Anders , Nilsson Kenneth , Jernberg-Wiklund Helena
Published: December 2003

Circumvention of chemoresistance in the B-cell neoplasm multiple myeloma (MM) might be achieved by targeting certain intracellular signaling pathways crucial for survival of the malignant clone. The use of the macrolide rapamycin, selectively inhibiting the phosphoprotein mammalian target of rapamycin (mTOR) downstream of, for example, insulin-like growth factor-I receptor (IGF-IR), possibly represents such a molecular mode of therapy. By using a panel of MM cell lines we showed that rapamycin induced G0/G1 arrest, an effect being associated with an increase of the cyclin-dependent kinase inhibitor p27 and a decrease of cyclins D2 and D3. Interestingly, in primary, mainly noncycling MM cells, rapamycin, at clinically achievable concentrations, induced apoptosis. More important, rapamycin sensitized both MM cell lines and primary MM cells to dexamethasone-induced apoptosis. This effect was associated with a decreased expression of cyclin D2 and survivin. The phosphorylation of the serine/threonine kinase p70S6K at Thr389 and Thr421/Ser424 was down-regulated by rapamycin and/or dexamethasone. Strikingly, the combinatorial treatment with rapamycin and dexamethasone suppressed the antiapoptotic effects of exogenously added IGF-I and interleukin 6 (IL-6) as well as their stimulation of p70S6K phosphorylation. The induction of apoptosis by rapamycin and dexamethasone despite the presence of survival factors was also demonstrated in primary MM cells, thus suggesting this drug combination to be active also in vivo. (Blood. 2004;103:3138-3147)
Fenretinide enhances rituximab-induced cytotoxicity against B-cell lymphoma xenografts through a caspase-dependent mechanism
Authors: Gopal Ajay K. , Pagel John M. , Hedin Nathan , Press Oliver W.
Published: December 2003

The anti-CD20 monoclonal antibody rituximab induces remission in 40% to 60% of patients with indolent B-cell lymphoma, but virtually all patients have relapses. We evaluated the efficacy of concurrent administration of another biologic agent, N-(4-hydroxyphenyl) retinamide (4HPR, fenretinide) with rituximab against a variety of human B-cell lymphoma cell lines (Ramos, DHL-4, and FL-18) in vivo. Concurrent 4HPR and rituximab administration prevented tumor progression of lymphoma-bearing mice in a minimal disease model (rituximab + 4HPR, 100% progression free; rituximab alone, 37.5% progression free, P = .01; 4HPR alone, 12.5% progression free, P < .01; controls, 0% progression free, P < .01). Combinations of 4HPR + rituximab exceeded the predicted 50% additive rate of disease control from each agent alone (P = .038). Administering 4HPR and rituximab to mice with established tumors induced complete responses (CRs) in 80% of animals compared with 20% to 40% CRs using either agent alone (P = .07), resulting in significantly improved survival. Tumors harvested from 4HPR + rituximab-treated mice displayed elevated caspase activation compared with untreated controls (P = .02). Adding a broad-spectrum caspase inhibitor in vivo fully abrogated the antitumor effects of 4HPR + rituximab (P = .05). These results establish the efficacy of 4HPR/rituximab combinations, confirm their caspase-mediated mechanism of action, and offer the potential for disease control with minimal toxicity for patients with B-cell malignancies. (Blood. 2004;103:3516-3520)
Th2 cells are less susceptible than Th1 cells to the suppressive activity of CD25+ regulatory thymocytes because of their responsiveness to different cytokines
Authors: Cosmi Lorenzo , Liotta Francesco , Angeli Roberta , Mazzinghi Benedetta , Santarlasci Veronica , Manetti Roberto , Lasagni Laura , Vanini Vittorio , Romagnani Paola , Maggi Enrico , Annunziato Francesco , Romagnani Sergio
Published: December 2003

T-cell clones generated from both CD4+CD25+ and CD8+CD25+ human thymocytes were assessed for their ability to suppress the proliferative response to allogeneic stimulation of type 1 T-helper (Th1) or type 2 T-helper (Th2) clones derived from autologous CD4+CD25- thymocytes. Both CD4+ and CD8+ T-regulatory (Treg) cells completely suppressed the proliferation of Th1 clones but exhibited significantly lower suppressive activity on the proliferation of Th2 clones. The partial suppressive effect on Th2 cells was further reduced by the addition in culture of interleukin-4 (IL-4), whereas it was increased in the presence of an anti–IL-4 monoclonal antibody (mAb). The suppressive activity on Th2 clones was also completely inhibited by the addition of IL-7, IL-9, and IL-15 but not of IL-2, whereas the suppressive effect on Th1 clones was only reverted by the addition of IL-15. Of note, Th2 clones expressed significantly higher amounts of mRNA for IL-4 receptor (IL-4R) and IL-9R α chains than Th1 clones, whereas the expression of mRNA for IL-2R, IL-7R, and IL-15R α chains was comparable. Taken together, these findings demonstrate that Th2 cells have a lower susceptibility than Th1 cells to the suppressive activity of human CD25+ regulatory thymocytes, because they are able to produce, and to respond to, growth factors distinct from IL-2, such as IL-4 and IL-9. (Blood. 2004; 103:3117-3121)
Missense or splicing mutation? The case of a fibrinogen Bβ-chain mutation causing severe hypofibrinogenemia
Authors: Asselta Rosanna , Duga Stefano , Spena Silvia , Peyvandi Flora , Castaman Giancarlo , Malcovati Massimo , Mannucci Pier Mannuccio , Tenchini Maria Luisa
Published: December 2003

The genetic basis of severe hypofibrinogenemia was analyzed in a 57-year-old Italian woman. She turned out to be a compound heterozygote for a novel putative missense mutation (Leu172Gln) and a previously described nonsense mutation (Arg17Stop) in the fibrinogen Bβ-chain gene. The pathogenetic role of Leu172Gln was analyzed by in vitro expression of the mutant recombinant protein in COS-1 cells. These experiments demonstrated that mutant Bβ-Leu172Gln fibrinogen was normally assembled and secreted. Inspection of the nucleotide sequence surrounding the mutation suggested a possible role on pre–messenger RNA (mRNA) splicing. Production of the mutant transcript in HeLa cells confirmed that the mutation activates a cryptic acceptor splice site in exon 4, resulting in a truncated Bβ chain, lacking approximately 70% of the C-terminal region. This represents the first exonic splicing mutation identified in the fibrinogen genes. These findings strengthen the importance to analyze potentially pathogenetic nucleotide variations at both the protein and the mRNA level. (Blood. 2004; 103:3051-3054)
High-dose imatinib mesylate therapy in newly diagnosed Philadelphia chromosome–positive chronic phase chronic myeloid leukemia
Authors: Kantarjian Hagop , Talpaz Moshe , O'Brien Susan , Garcia-Manero Guillermo , Verstovsek Srdan , Giles Francis , Rios Mary Beth , Shan Jianqin , Letvak Laurie , Thomas Deborah , Faderl Stefan , Ferrajoli Alessandra , Cortes Jorge
Published: December 2003

Imatinib mesylate (STI571) is effective in chronic phase chronic myelogenous leukemia (CML). However, most patients treated with 400 mg imatinib daily have variable levels of residual molecular disease. We treated 114 patients with newly diagnosed chronic phase CML with 400 mg imatinib twice daily. Overall, 109 patients (96%) had a major cytogenetic response (Philadelphia chromosome [Ph] < 35%), and 103 (90%) had a complete response (Ph 0%). With a median follow-up of 15 months, no patient has progressed to accelerated or blastic phase. The estimated 2-year survival rate was 94%. By quantitative polymerase chain reaction (QPCR) studies, 71 (63%) of 112 patients showed BCR-ABL/ABL percentage ratios decrease to less than 0.05%, and 31 (28%) to undetectable levels. Compared with standard-dose imatinib, high-dose imatinib was associated with significantly better complete cytogenetic response (P = .0005), major molecular response (QPRC < 0.05%; P = .00001), and complete molecular response (undetectable BCR-ABL; P = .001). High-dose imatinib was well tolerated but resulted in more frequent myelosuppression; 82% of patients continue to receive 600 mg or more of imatinib daily. In conclusion, high-dose imatinib induced higher rates of complete cytogenetic response and of molecular response in patients with newly diagnosed chronic phase CML. (Blood. 2004; 103:2873-2878)
Macrophage activation and Fcγ receptor-mediated signaling do not require expression of the SLP-76 and SLP-65 adaptors
Authors: Nichols Kim E , Haines Kathleen , Myung Peggy S , Newbrough Sally , Myers Erin , Jumaa Hassan , Shedlock Devon J , Shen Hao , Koretzky Gary A
Published: December 2003

The Src-homology 2 domain-containing, leukocyte-specific phosphoprotein of 76 kDa (SLP-76) is a hematopoietic adaptor that plays a central role during immunoreceptor-mediated activation of T lymphocytes and mast cells and collagen receptor-induced activation of platelets. Despite similar levels of expression in macrophages, SLP-76 is not required for Fc receptor for immunoglobulin G (IgG; FcγR)-mediated activation. We hypothesized that the related adaptor SLP-65, which is also expressed in macrophages, may compensate for the loss of SLP-76 during FcγR-mediated signaling and functional events. To address this hypothesis, we examined bone marrow-derived macrophages (BMM) from wild-type (WT) mice or mice lacking both of these adaptors. Contrary to our expectations, SLP-76−/− SLP-65−/− BMM demonstrated normal FcγR-mediated activation, including internalization of Ig-coated sheep red blood cells and production of reactive oxygen intermediates. FcγR-induced biochemical events were normal in SLP-76−/− SLP-65−/− BMM, including phosphorylation of phospholipase C and the extracellular signaling-regulated kinases 1 and 2. To determine whether macrophages functioned normally in vivo, we infected WT and SLP-76−/− SLP-65−/− mice with sublethal doses of Listeria monocytogenes (LM), a bacterium against which the initial host defense is provided by activated macrophages. WT and SLP-76−/− SLP-65−/− mice survived acute, low-dose infection and showed no difference in the number of liver or spleen LM colony-forming units, a measure of the total body burden of this organism. Taken together, these data suggest that neither SLP-76 nor SLP-65 is required during FcγR-dependent signaling and functional events in macrophages.
Mouse bone marrow contains large numbers of functionally competent neutrophils
Authors: Boxio Rachel , Bossenmeyer-Pourié Carine , Steinckwich Natacha , Dournon Christian , Nüße Oliver
Published: December 2003

The mouse has become an important model for immunological studies including innate immunity. Creating transgenic mice offers unique possibilities to study gene-function relationships. However, relatively little is known about the physiology of neutrophils from wild-type mice. Do they behave like human neutrophils, or are there species-specific differences that need to be considered when extrapolating results from mice to humans? How do we isolate neutrophils from mice? For practical reasons, many studies on mouse neutrophils are done with bone marrow cells. However, human bone marrow neutrophils appear to be heterogeneous and functionally immature. We have isolated and compared neutrophils from mouse bone marrow and from peripheral blood obtained by tail bleeding. Using the same Percoll® density gradient for both preparations, we have obtained morphologically mature neutrophils from bone marrow and blood. Both cell populations responded to formylmethionyl-leucyl-phenylalanine (fMLF) with primary and secondary granule release and superoxide production. Quantitative analysis of our data revealed minor differences between cells from bone marrow and blood. Superoxide production and primary granule release were stimulated at lower fMLF concentrations in blood neutrophils. However, the amplitude and the kinetics of maximal responses were similar. The principal difference was the lifespan of the two cell populations. Bone marrow cells survived significantly longer in culture, which may suggest that they are receiving antiapoptic signals that are absent in the blood. Our data suggest that mice have a large reservoir of functionally competent neutrophils in their bone marrow. This reservoir may be needed to replace circulating neutrophils rapidly during infection.
p38 activation through Toll-like receptors modulates IFN-γ-induced expression of the Tap-1 gene only in macrophages
Authors: Cecil Alicia A , Klemsz Michael J
Published: December 2003

Although interferon-γ (IFN-γ) induces the transporter associated with antigen processing (Tap)-1 expression in macrophages, cooperation with lipopolysaccharide signaling through Toll-like receptor 4 (TLR4) accelerates the kinetics and increases the overall levels of this gene. In this report, we show that peptidoglycan signaling through TLR2 and bacterial CpG DNA signaling through TLR9 are functionally equivalent at synergizing with IFN-γ in regulating Tap-1 expression in macrophages. Activation of the p38 mitogen-activated protein kinase is necessary for this response, which correlates with increased phosphorylation of signal transducer and activator of transcription-1 on serine 727. Activation of p38, however, is not sufficient, as this signaling event does not affect the response to IFN-γ in HeLa cells. The cooperation between these different signaling pathways also requires membrane fluidity. These data suggest that macrophages possess an ability to coordinate the signaling between the IFN-γ and TLR receptors.
End-stage differentiation of neutrophil granulocytes in vivo is accompanied by up-regulation of p27kip1 and down-regulation of CDK2, CDK4, and CDK6
Authors: Klausen Pia , Bjerregaard Malene Digmann , Borregaard Niels , Cowland Jack Bernard
Published: December 2003

The in vivo expression profiles of cell-cycle proteins regulating G1-to-S-phase transition were determined in three neutrophil precursor populations from human bone marrow: myeloblasts (MBs) and promyelocytes (PMs); myelocytes (MCs) and metamyelocytes (MMs); and band cells (BCs) and segmented neutrophil cells (SCs) and in mature polymorphonuclear neutrophils (PMNs) from peripheral blood. Complete cell-cycle arrest was observed in BCs/SCs and PMNs. Cyclins D1, D2, and D3 were found to be down-regulated during granulopoiesis, whereas a slight increase of cyclin E was seen. In contrast, cyclin-dependent kinase (CDK)2, -4, and -6 were down-regulated from the MC/MM stages and onward. The transcript levels of CDK2, -4, and -6 were concurrently down-regulated. As the only CDK inhibitor, p27kip1 protein and mRNA expression were up-regulated in MCs/MMs and reached peak levels in PMNs. Protein expression of retinoblastoma protein and the related pocket proteins p107 and p130 was down-regulated from the MC/MM stages and onward. This is the first report to describe expression levels of cell-cycle proteins during granulopoiesis in vivo, and it strongly contrasts the observations made in cell-culture systems in vitro.
Impact of Hospital Procedure Volume on Surgical Operation and Long-Term Outcomes in High-Risk Curatively Resected Rectal Cancer: Findings From the Intergroup 0114 Study
Authors: Meyerhardt Jeffrey A. , Tepper Joel E. , Niedzwiecki Donna , Hollis Donna R. , Schrag Deborah , Ayanian John Z. , O'Connell Michael J. , Weeks Jane C. , Mayer Robert J. , Willett Christopher G. , MacDonald John S. , Benson Al B. , Fuchs Charles S.
Published: December 2003

Purpose

Prior studies have demonstrated superior outcomes after a curative surgical resection of rectal cancer at hospitals where the volume of such surgeries is high. However, because these studies often lack detailed information on tumor and treatment characteristics as well as cancer recurrence, the true nature of this relation remains uncertain.

Patients and Methods

We studied a nested cohort of 1,330 patients with stage II and stage III rectal cancer participating in a multicenter, adjuvant chemoradiotherapy trial. We analyzed differences in rates of sphincter-preserving operations, overall survival, and cancer recurrence by hospital surgical volume.

Results

We observed a significant difference in the rates of abdominoperineal resections across tertiles of hospital procedure volume (46.3% for patients resected at low-volume, 41.3% at medium-volume, and 31.8% at high-volume hospitals; P < .0001), even after adjustment for tumor distance from the anal verge. However, this higher rate of sphincter-sparing operations at high-volume centers was not accompanied by any increase in recurrence rates. Hospital surgical volume did not predict overall, disease-free, recurrence-free, or local recurrence-free survival. However, among patients who did not complete the planned adjuvant chemoradiotherapy (270 patients), those who underwent surgery at low-volume hospitals had a significant increase in cancer recurrence (adjusted hazard ratio, 1.94; 95% CI, 1.01 to 3.72; P = .04 for the trend) and a nonsignificant trend toward increased overall mortality (P = .08) and local recurrence (P = .10). In contrast, no significant volume-outcome relation was noted among patients who did complete postoperative therapy.

Conclusion

Using prospectively recorded data, we found that hospital surgical volume had no significant effect on rectal cancer recurrence or survival when patients completed standard adjuvant therapy. Sphincter-preserving surgery was more commonly performed at high-volume centers.
Group II Rhabdomyosarcoma and Rhabdomyosarcomalike Tumors: Is Radiotherapy Necessary?
Authors: Schuck Andreas , Mattke Adrian C. , Schmidt Bernhard , Kunz Denise S. , Harms Dieter , Knietig Robert , Treuner Joern , Koscielniak Ewa
Published: December 2003

Purpose

In the prospective Cooperative Soft Tissue Sarcoma Study Group (CWS) 81, 86, 91, and 96 trials, radiotherapy was omitted in some patients with rhabdomyosarcoma and rhabdomyosarcoma-like tumors within Intergroup Rhabdomyosarcoma Study (IRS) group II. This analysis evaluates whether subgroups can be defined for which radiotherapy is not necessary.

Patients and Methods

Two hundred three patients who were registered between January 1981 and December 1998 were eligible for evaluation. Radiotherapy was given depending on tumor location, histology, and whether a secondary complete resection could be performed. The recommended radiation doses ranged from 32 to 54 Gy.

Results

One hundred ten patients did receive and 93 patients did not receive radiotherapy. The calculated local control after 5 years was 83% with and 65% without radiotherapy (P < .004). Event-free survival (EFS) at 5 years was 76% and 58%, respectively (P < .005). Overall survival (OS) at 5 years was 84% and 77% (P = not significant). The differences in local control were significant for the subgroups of irradiated patients with favorable histology, favorable site, and initial tumor size of less than 5 cm. A trend for improved local control with irradiation was observed for patients with unfavorable site, unfavorable histology, and large primary tumors. EFS was significantly improved for irradiated patients who had unfavorable histology, both favorable and unfavorable tumor sites, and small initial tumors. OS was significantly improved for patients with unfavorable histology through radiation.

Conclusion

Local control and EFS in group II patients are improved with radiotherapy. No subgroup could be defined for which the omission of radiotherapy produced outcome equivalent to that of patients who were irradiated.
Phase I Trial of Combined-Modality Therapy for Localized Esophageal Cancer: Escalating Doses of Continuous-Infusion Paclitaxel With Cisplatin and Concurrent Radiation Therapy
Authors: Brenner Baruch , Ilson David H. , Minsky Bruce D. , Bains Manjit S. , Tong William , Gonen Mithat , Kelsen David P.
Published: December 2003

Purpose

To define the maximum-tolerated dose (MTD) of paclitaxel when given as a weekly 96-hour infusion with cisplatin and radiotherapy for patients with esophageal cancer.

Patients and Methods

Thirty-four patients with locally advanced esophageal cancer and three patients with local recurrence or positive resection margins were treated. Weekly paclitaxel doses of 10, 20, 30, 40, 60, and 80 mg/m2, given as a continuous 96-hour infusion, were administered with weekly cisplatin, 30 mg/m2 on day 1, weeks 1 to 6, and concurrent radiation (50.4 Gy). Plasma paclitaxel steady-state levels were measured.

Results

Dose-limiting toxicity, defined as a treatment break longer than 2 weeks for toxicity, occurred in one patient in the 80-mg/m2/wk dose level. Major causes for any (including ≤ 2 weeks) treatment breaks were mediport complications and neutropenic fever, which occurred mostly at that dose level. At a paclitaxel dose of 60 mg/m2/wk, myelosuppression, mostly neutropenia, was relatively mild and transient; stomatitis, esophagitis, diarrhea. and peripheral neuropathy were uncommon and usually of grade 2 or less. Therefore, the MTD was established at 60 mg/m2/wk. The mean steady-state concentration of paclitaxel at the MTD was 17.2 nmol/L. Complete (R0) resection was possible in 16 (73%) of 22 patients who underwent subsequent surgery, and the pathologic complete response rate was 24%.

Conclusion

Weekly, 96-hour infusion of paclitaxel 60 mg/m2/wk, given with concurrent cisplatin and radiotherapy, is a safe and tolerable regimen for patients with localized esophageal cancer. Preliminary efficacy data are encouraging. This regimen is the basis of ongoing Radiation Therapy Oncology Group phase II randomized trials in esophageal and gastric cancers.
Phase I Study of the Humanized Antiepidermal Growth Factor Receptor Monoclonal Antibody EMD72000 in Patients With Advanced Solid Tumors That Express the Epidermal Growth Factor Receptor
Authors: Vanhoefer Udo , Tewes Mitra , Rojo Federico , Dirsch Olaf , Schleucher Norbert , Rosen Oliver , Tillner Joachim , Kovar Andreas , Braun Ada H. , Trarbach Tanja , Seeber Siegfried , Harstrick Andreas , Baselga José
Published: December 2003

Purpose

To investigate the safety and tolerability and to explore the pharmacokinetic and pharmacodynamic profile of the humanized antiepidermal growth factor receptor monoclonal antibody EMD72000 in patients with solid tumors that express epidermal growth factor receptor (EGFR).

Patients and Methods

This was a phase I dose-escalation trial of EMD72000 in patients with advanced, EGFR-positive, solid malignancies that were not amenable to any established chemotherapy or radiotherapy treatment. EMD72000 was administered weekly without routine premedication until disease progression or unacceptable toxicity.

Results

Twenty-two patients were treated with EMD72000 at five different dose levels (400 to 2,000 mg/wk). National Cancer Institute common toxicity criteria grade 3 headache and fever occurring after the first infusion were dose limiting at 2,000 mg/wk; thus, the maximum-tolerated dose was 1,600 mg/wk. No other severe side effects, especially no allergic reactions or diarrhea, were observed. Acneiform skin reaction was the most common toxicity, but it was mild, with grade 1 in 11 patients (50%) and grade 2 in three patients (14%). Pharmacokinetic analyses demonstrated a predictable pharmacokinetic profile for EMD72000 . Pharmacodynamic studies on serial skin biopsies revealed that EMD72000 effectively abrogated EGFR-mediated cell signaling (eg, reduced phosphorylation of EGFR and mitogen-activated protein kinase), with no alteration in total EGFR protein. Objective responses (23%; 95% CI, 8% to 45%) and disease stabilization (27%; 95% CI, 11% to 50%) were achieved at all dose levels, and responding patients received treatment for up to 18 months without cumulative toxicity.

Conclusion

Treatment with EMD72000 was well tolerated and showed evidence of activity in heavily pretreated patients with EGFR-expressing tumors. EMD72000 at the investigated doses significantly inhibited downstream EGFR-dependent processes.
Neurocognitive Function and Progression in Patients With Brain Metastases Treated With Whole-Brain Radiation and Motexafin Gadolinium: Results of a Randomized Phase III Trial
Authors: Meyers Christina A. , Smith Jennifer A. , Bezjak Andrea , Mehta Minesh P. , Liebmann James , Illidge Tim , Kunkler Ian , Caudrelier Jean-Michel , Eisenberg Peter D. , Meerwaldt Jacobus , Siemers Ross , Carrie Christian , Gaspar Laurie E. , Curran Walter , Phan See-Chun , Miller Richard A. , Renschler Markus F.
Published: December 2003

Purpose

To report the neurocognitive findings in a phase III randomized trial evaluating survival and neurologic and neurocognitive function in patients with brain metastases from solid tumors receiving whole-brain radiation therapy (WBRT) with or without motexafin gadolinium (MGd).

Patients and Methods

Patients were randomly assigned to receive WBRT 30 Gy in 10 fractions with or without MGd 5 mg/kg/d. Monthly neurocognitive testing for memory, executive function, and fine motor skill was performed.

Results

Four hundred one patients were enrolled (251 with non–small-cell lung cancer, 75 with breast cancer, and 75 with other cancers); 90.5% patients had impairment of one or more neurocognitive tests at baseline. Neurocognitive test scores of memory, fine motor speed, executive function, and global neurocognitive impairment at baseline were correlated with brain tumor volume and predictive of survival. There was no statistically significant difference between treatment arms in time to neurocognitive progression. Patients with lung cancer (but not other types of cancer) who were treated with MGd tended to have improved memory and executive function (P = .062) and improved neurologic function as assessed by a blinded events review committee (P = .048).

Conclusion

Neurocognitive tests are a relatively sensitive measure of brain functioning; a combination of tumor prognostic variables and brain function assessments seems to predict survival better than tumor variables alone. Although the addition of MGd to WBRT did not produce a significant overall improvement between treatment arms, MGd may improve memory and executive function and prolong time to neurocognitive and neurologic progression in patients with brain metastases from lung cancer.
Multicenter Phase II Study of Nordic Fluorouracil and Folinic Acid Bolus Schedule Combined With Oxaliplatin As First-Line Treatment of Metastatic Colorectal Cancer
Authors: Sørbye Halfdan , Glimelius Bengt , Berglund Åke , Fokstuen Tone , Tveit Kjell Magne , Brændengen Morten , Øgreid Dagfinn , Dahl Olav
Published: December 2003

Purpose

This Nordic multicenter phase II study evaluated the efficacy and safety of oxaliplatin combined with the Nordic bolus schedule of fluorouracil (FU) and folinic acid (FA) as first-line treatment in metastatic colorectal cancer.

Patients and Methods

Eighty-five patients were treated with oxaliplatin 85 mg/m2 as a 2-hour infusion on day 1, followed by a 3-minute bolus injection with FU 500 mg/m2 and, 30 minutes later, by a bolus injection with FA 60 mg/m2 every second week. The same doses of FU and FA were also given on day 2.

Results

Fifty-one of 82 assessable patients achieved a complete (n = 4) or partial (n = 47) response, leading to a response rate of 62% (95% CI, 52% to 72%). Nineteen patients showed stable disease, and 12 patients had progressive disease. Thirty-eight of the 51 responses were radiologically confirmed 8 weeks later (confirmed response rate, 46%; 95% CI, 36% to 58%). The estimated median time to progression was 7.0 months (95% CI, 6.3 to 7.7 months), and the median overall survival was 16.1 months (95% CI, 12.7 to 19.6 months) in the intent-to-treat population. Neutropenia was the main adverse event, with grade 3 to 4 toxicity in 58% of patients. Febrile neutropenia developed in seven patients. Nonhematologic toxicity consisted mainly of neuropathy (grade 3 in 11 patients and grade 2 in another 27 patients).

Conclusion

Oxaliplatin combined with the bolus Nordic schedule of FU+FA (Nordic FLOX) is a well-tolerated, effective, and feasible bolus schedule as first-line treatment of metastatic colorectal cancer that yields comparable results compared with more complex schedules.
Multicenter Phase II Study of Erlotinib, an Oral Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitor, in Patients With Recurrent or Metastatic Squamous Cell Cancer of the Head and Neck
Authors: Soulieres Denis , Senzer Neil N. , Vokes Everett E. , Hidalgo Manuel , Agarwala Sanjiv S. , Siu Lillian L.
Published: December 2003

Purpose

To determine the efficacy and safety profiles of erlotinib in patients with advanced recurrent and/or metastatic squamous cell cancer of the head and neck (HNSCC).

Patients and Methods

Patients with locally recurrent and/or metastatic HNSCC, regardless of their HER1/EGFR status, were treated with erlotinib at an initial dose of 150 mg daily. Dose reductions or escalations were allowed based on tolerability of erlotinib.

Results

One-hundred fifteen patients were enrolled onto this study. Forty-seven percent of patients received erlotinib at 150 mg daily throughout the entire study, 6% had dose escalations, and 46% required dose reductions and/or interruptions. Five patients achieved partial responses on study, for an overall objective response rate of 4.3% (95% CI, 1.4% to 9.9%). Disease stabilization was maintained in 44 patients (38.3%) for a median duration of 16.1 weeks. The median progression-free survival was 9.6 weeks (95% CI, 8.1 to 12.1 weeks), and the median overall survival was 6.0 months (95% CI, 4.8 to 7.0 months). Subgroup analyses revealed a significant difference in overall survival favoring patients who developed at least grade 2 skin rashes versus those who did not (P = .045), whereas no difference was detected based on HER1/EGFR expression. Rash and diarrhea were the most common drug-related toxicities, encountered in 79% and 37% of patients, respectively, though the severity was mild to moderate in most cases.

Conclusion

Erlotinib was well tolerated in this heavily pretreated HNSCC population and produced prolonged disease stabilization; hence, further evaluation of its role in this tumor type is warranted.
Phase II Trial of PS-341 in Patients With Renal Cell Cancer: A University of Chicago Phase II Consortium Study
Authors: Davis Nancy B. , Taber David A. , Ansari Rafat H. , Ryan Christopher W. , George Christopher , Vokes Everett E. , Vogelzang Nicholas J. , Stadler Walter M.
Published: December 2003

Purpose

Determine response rate, time to disease progression, and toxicity of the proteasome inhibitor PS-341 in patients with stage IV renal cell cancer.

Patients and Methods

PS-341 1.5 mg/m2 was administered intravenously twice weekly for 2 weeks every 21 days. Dose escalation to 1.7 mg/m2 ensued in the absence of grade 3 to 4 toxicities. Re-evaluation took place after three cycles. To assess proteasome inhibition, patients were randomly assigned to tumor core biopsy either before the first dose or after the third cycle of PS-341. Additionally, whole blood was collected at the same time intervals.

Results

Twenty-three patients were enrolled; 21 were assessable for response. Two patients were never treated (one patient refused treatment and one had insufficient tumor for biopsy). Eighteen patients completed at least three cycles of therapy; three patients experienced disease progression after two cycles. Grade 4 toxicities were arthralgia, diarrhea, and vomiting. Grade 3 toxicities included thrombocytopenia with one hemorrhage, anemia, febrile neutropenia, gastrointestinal toxicity, pain, fatigue, neuropathy (one sensory, one mixed sensorimotor), and electrolyte disturbances. Grade 1 to 2 neuropathy occurred in seven patients. One case of thrombosis and one case of pleural effusion occurred. Only one objective response was seen. Proteasome activity was measured by specific chymotryptic activity (SpA) and chymotryptic/tryptic activity (ChT:T). After PS-341, there was a decrease in mean whole blood SpA and ChT:T (P = .07 and .11, respectively).

Conclusion

Evidence is lacking for clinically significant activity of PS-341 in metastatic renal cell cancer. Insufficient biopsy and whole blood sample numbers preclude conclusions regarding proteasome inhibition within tumor. Further evaluation in this disease setting is not recommended.