bluuebunny/crossref_metadata_2025 huggingface dataset:
Dietary grape seed proanthocyanidins inhibit UVB-induced oxidative stress and activation of mitogen-activated protein kinases and nuclear factor-κB signaling in in vivo SKH-1 hairless mice
Authors: Sharma Som D. , Meeran Syed M. , Katiyar Santosh K.
Published: March 2007

We have shown previously that dietary grape seed proanthocyanidins (GSP) inhibit UVB-induced photocarcinogenesis in mice. As UVB-induced oxidative stress and oxidative stress–mediated signaling has been implicated in photocarcinogenesis, this study was designed to investigate the effect of dietary GSPs on UVB-induced oxidative stress in in vivo SKH-1 hairless mice. Here, we report that provision of dietary GSPs (0.2 and 0.5%, w/w) to mice exposed to either acute UVB irradiation (120 mJ/cm2) or chronic irradiation of UVB inhibited depletion of glutathione peroxidase, catalase, and glutathione, and inhibited UVB-induced H2O2, lipid peroxidation, protein oxidation, and nitric oxide in mouse skin. As UV-induced oxidative stress mediates activation of mitogen-activated protein kinase (MAPK) and nuclear factor-κB (NF-κB) signaling pathways, we determined the effect of dietary GSPs on these pathways. We observed that dietary GSPs inhibited UVB-induced phosphorylation of extracellular signal-regulated kinase 1/2, c-Jun-NH2-kinase, and p38 proteins of MAPK family, which seems to be mediated through reactivation of MAPK phosphatases. GSPs inhibited UVB-induced activation of NF-κB/p65 through inhibition of degradation of IκBα and activation of IκB kinase α (IKKα). As NF-κB–targeted genes play critical roles in inflammation and cellular proliferation, we assessed the effect of GSPs on proteins encoded by these genes. Dietary GSPs resulted in inhibition of the expression of proliferating cell nuclear antigen, cyclin D1, inducible nitric oxide synthase, and cyclooxygenase-2 in the skin. Collectively, our data show that GSPs have the ability to protect the skin from the adverse effects of UVB radiation via modulation of the MAPK and NF-κB signaling pathways and provide a molecular basis for the photoprotective effects of GSPs in an in vivo animal model. [Mol Cancer Ther 2007;6(3):995–1005]
Inactivation of glycogen synthase kinase-3β, a downstream target of the raf-1 pathway, is associated with growth suppression in medullary thyroid cancer cells
Authors: Kunnimalaiyaan Muthusamy , Vaccaro Abram M. , Ndiaye Mary A. , Chen Herbert
Published: March 2007

Glycogen synthase kinase-3β (GSK-3β) is an important regulator of cell proliferation and survival. Conflicting observations have been reported regarding the regulation of GSK-3β and extracellular signal–regulated kinase (ERK1/2) in cancer cells. In this study, we found that raf-1 activation in human medullary thyroid cancer cells, TT cells, resulted in phosphorylation of GSK-3β. Inactivation of GSK-3β in TT cells with well-known GSK-3β inhibitors such as lithium chloride (LiCl) and SB216763 is associated with both growth suppression and a significant decrease in neuroendocrine markers such as human achaete-scute complex-like 1 and chromogranin A. Growth inhibition by GSK-3β inactivation was found to be associated with cell cycle arrest due to an increase in the levels of cyclin-dependent kinase inhibitors such as p21, p27, and p15. Additionally, LiCl-treated TT xenograft mice had a significant reduction in tumor volume compared with those treated with control. For the first time, we show that GSK-3β is a key downstream target of the raf-1 pathway in TT cells. Also, our results show that inactivation of GSK-3β alone is sufficient to inhibit the growth of TT cells both in vitro and in vivo. [Mol Cancer Ther 2007;6(3):1151–8]
Identification of molecular characteristics correlated with glioblastoma sensitivity to EGFR kinase inhibition through use of an intracranial xenograft test panel
Authors: Sarkaria Jann N. , Yang Lin , Grogan Patrick T. , Kitange Gaspar J. , Carlson Brett L. , Schroeder Mark A. , Galanis Evanthia , Giannini Caterina , Wu Wenting , Dinca Eduard B. , James C. David
Published: March 2007

In the current study, we examined a panel of serially passaged glioblastoma xenografts, in the context of an intracranial tumor therapy response model, to identify associations between glioblastoma molecular characteristics and tumor sensitivity to the epidermal growth factor receptor (EGFR) kinase inhibitor erlotinib. From an initial evaluation of 11 distinct glioblastoma xenografts, two erlotinib-sensitive tumors were identified, each having amplified EGFR and expressing wild-type PTEN. One of these tumors expressed truncated EGFRvIII, whereas the other expressed full-length EGFR. Subsequent cDNA sequence analysis revealed the latter tumor as expressing an EGFR sequence variant with arginine, rather than leucine, at amino acid position 62; this was the only EGFR sequence variant identified among the 11 xenografts, other than the aforementioned vIII sequence variant. EGFR cDNAs were then examined from 12 more xenografts to determine whether additional missense sequence alterations were evident, and this analysis revealed one such case, expressing threonine, rather than alanine, at amino acid position 289 of the extracellular domain. This glioblastoma was also amplified for EGFR, but did not display significant erlotinib sensitivity, presumably due to its lacking PTEN expression. In total, our study identified two erlotinib-sensitive glioblastoma xenografts, with the common molecular characteristics shared by each being the expression of wild-type PTEN in combination with the expression of amplified and aberrant EGFR. [Mol Cancer Ther 2007;6(3):1167–74]
Mechanisms of Vascular Smooth Muscle Cell Migration
Authors: Gerthoffer William T.
Published: March 2007

Smooth muscle cell migration occurs during vascular development, in response to vascular injury, and during atherogenesis. Many proximal signals and signal transduction pathways activated during migration have been identified, as well as components of the cellular machinery that affect cell movement. In this review, a summary of promigratory and antimigratory molecules belonging to diverse chemical and functional families is presented, along with a summary of key signaling events mediating migration. Extracellular molecules that modulate migration include small biogenic amines, peptide growth factors, cytokines, extracellular matrix components, and drugs used in cardiovascular medicine. Promigratory stimuli activate signal transduction cascades that trigger remodeling of the cytoskeleton, change the adhesiveness of the cell to the matrix, and activate motor proteins. This review focuses on the signaling pathways and effector proteins regulated by promigratory and antimigratory molecules. Prominent pathways include phosphatidylinositol 3-kinases, calcium-dependent protein kinases, Rho-activated protein kinase, p21-activated protein kinases, LIM kinase, and mitogen-activated protein kinases. Important downstream targets include myosin II motors, actin capping and severing proteins, formins, profilin, cofilin, and the actin-related protein-2/3 complex. Actin filament remodeling, focal contact remodeling, and molecular motors are coordinated to cause cells to migrate along gradients of chemical cues, matrix adhesiveness, or matrix stiffness. The result is recruitment of cells to areas where the vessel wall is being remodeled. Vessel wall remodeling can be antagonized by common cardiovascular drugs that act in part by inhibiting vascular smooth muscle cell migration. Several therapeutically important drugs act by inhibiting cell cycle progression, which may reduce the population of migrating cells.
Interferon-γ Axis in Graft Arteriosclerosis
Authors: Tellides George , Pober Jordan S.
Published: March 2007

Cardiac transplantation is the most effective treatment for advanced heart failure. Despite improvements in immunosuppression therapy that prevent acute rejection, cardiac allografts fail at rates of 3% to 5% per posttransplant year. The hallmark morphological lesion of chronically failing cardiac allografts, also seen in chronic renal and liver graft failure, is luminal stenosis of blood vessels, especially of conduit arteries. Late graft failure results from widespread secondary ischemic injury to the graft parenchyma rather than direct immune-mediated damage. Although this process affects the entire graft vasculature, graft arteriosclerosis is a suitable term to describe the problem because it applies to different types of failing organs and because it emphasizes the central feature, namely an accelerated form of arterial injury and remodeling. The precise pathogenesis of graft arteriosclerosis is unknown. In this review, we make the case that the signature T-helper type 1 cytokine, interferon (IFN)-γ, is a key effector in graft arteriosclerosis, which, together with the IFN-γ–inducing cytokine interleukin-12 and IFN-γ–inducible chemokines such as CXCR3 ligands, constitute a positive feedback loop for T-cell activation, differentiation, and recruitment that we refer to as the IFN-γ axis. We evaluate the evidence to support this hypothesis in clinical observational and experimental animal studies. Additionally, we examine the regulation of IFN-γ production within the artery wall, the effects of IFN-γ on vessel wall cells, and the outcome of therapeutic agents on IFN-γ production and signaling. These observations lead us to suggest that new therapies for graft arteriosclerosis should be optimized which focus on reducing IFN-γ synthesis or actions.
Myocardin-Related Transcription Factors
Authors: Parmacek Michael S.
Published: March 2007

The association of transcriptional coactivators with DNA-binding proteins provides an efficient mechanism to expand and modulate genetic information encoded within the genome. Myocardin-related transcription factors (MRTFs), including myocardin, MRTF-A/MKL1/MAL, and MRTF-B/MKL2, comprise a family of related transcriptional coactivators that physically associate with the MADS box transcription factor, serum response factor, and synergistically activate transcription. MRTFs transduce cytoskeletal signals to the nucleus, activating a subset of serum response factor–dependent genes promoting myogenic differentiation and cytoskeletal organization. MRTFs are multifunctional proteins that share evolutionarily conserved domains required for actin-binding, homo- and heterodimerization, high-order chromatin organization, and transcriptional activation. Mice harboring loss-of-function mutations in myocardin, MRTF-A, and MRTF-B, respectively, display distinct phenotypes, including cell autonomous defects in vascular smooth muscle cell and myoepithelial cell differentiation and function. This article reviews the molecular basis of MRTF function with particular focus on the role MRTFs play in regulating cardiovascular patterning, vascular smooth muscle cell and cardiomyocyte differentiation and in the pathogenesis of congenital heart disease and vascular proliferative syndromes.
Making a Doughnut-shaped Egg Mass: Oviposition Behaviour of Vibrissaphora boringiae (Anura: Megophryidae)
Authors: Zheng Yuchi , Fu Jinzhong
Published: March 2007

Vibrissaphora boringiae produces doughnut-shaped egg masses (i.e., circular mass with central depression) that are attached to the underside of submerged rocks in running water. The oviposition behaviour of this species was observed for the first time, and explains how egg masses were shaped. The male used the right hindlimb to push the eggs up to the bottom surface of the rock, while the pair rotated horizontally and counter clockwise. Three limbs of the female provided the support and power for the rotation. The male was positioned on the dorsal-left side of the female, and formed a rare asymmetric inguinal amplexus. This type of oviposition behaviour may be common in megophryid frogs that produce doughnut-shaped and circular egg masses.
Courtship and mating behaviours of two syntopic species of skink (Plestiodon anthracinus and Plestiodon fasciatus)
Authors: Pyron Robert Alexander , Camp Carlos Duane
Published: March 2007

Courtship and mating behaviours are widely conserved throughout the scincid lizard genus Plestiodon, and ethological isolation between closely related species depends heavily on differentiating chemical cues. The purpose of this study was to determine whether or not subtle, as yet undetected differences are present in the mating behaviours of two syntopic, distantly related skinks, P. anthracinus and P. fasciatus. Observed courtship and mating behaviours were similar between the two species and to those reported for other species within this genus. However, survival analysis determined significant interspecific differences in the duration of pre-coital behaviours. Investigation of such subtle differences between species more closely related than these two may generate further insights into the evolution of ethological isolating mechanisms in lizards.
The influence of internote-interval variation of the advertisement call on the phonotactic behaviour in male Allobates femoralis (Dendrobatidae)
Authors: Hödl Walter , Franz Alexander , Göd Mario
Published: March 2007

Acoustic conspecific recognition depends on spectral and temporal call properties, but not all of these are necessary for species identification. To test the importance of the advertisement call's internote interval of the dendrobatid frog Allobates (=Epipedobates) femoralis, we conducted field playback experiments with modified conspecific calls and investigated phonotactic responses. Allobates femoralis males showed positive phonotaxis when calls with internote intervals varying up to ±60% of the population's mean were presented. No phonotactic approach was observed in response to modified advertisement calls containing internote intervals of the syntopic heterospecific leptodactylid frog Adenomera hylaedactyla. However, 26.7% of the A. femoralis males tested showed positive phototoxic when altered advertisement calls with internote intervals of the syntopic heterospecific dendrobatid frog Epipedobates cf. hahneli were presented. Our results show that only a combination of different acoustic call parameters provides correct species-specific recognition.
Promiscuity and high level of multiple paternity in common wall lizards (Podarcis muralis): data from microsatellite markers
Authors: Oppliger Anne , Degen Loic , John-Alder Henry-B. , Bouteiller-Reuter Caroline
Published: March 2007

Little is known about the mating system of the common wall lizard Podarcis muralis. Behavioural and observational data have demonstrated that females frequently mate with multiple males. However, the possible occurrence of multiple paternity has never been investigated. By using microsatellite paternity analysis in a wild population, we document this species indeed mate promiscuously and these matings resulted in multiple paternity in at least 87% of the clutches examined.
The effects of temperature and pH on the embryonic development of two species of Triturus (Caudata: Salamandridae)
Authors: Vignoli Leonardo , Bologna Marco , D'Amen Manuela
Published: March 2007

Amphibian populations are especially sensitive to aquatic parameters, in particular during embryonic and larval life. Our aim was to test for an effect of temperature (T = 13°C, 20°C and 25°C at constant pH = 7) and pH (pH = 5.5, 7 and 8.5 at constant T= 20°C) on embryos of two species of Triturus, T. carnifex carnifex and T. italicus (Amphibia, Salamandridae) using GLM procedure. Trend of embryogenesis processes, time to hatching and rate of development have a similar effect in both species in the used range of temperature and pH. Time to hatching decreased significantly with the increasing temperature. The pH experimental conditions had no effect on T. carnifex embryos survival, while the acidic pH condition raised the mortality rate in T. italicus, whose embryos should be more vulnerable than those of T. carnifex to acidification in nature.
Estimating population size in the European tree frog (Hyla arborea) using individual recognition and chorus counts
Authors: Helfer Véronique , Pellet Jérôme , Yannic Glenn
Published: March 2007

Chorus counts are widely used to assess population abundance in breeding anurans. It is however unclear how such counts translate into true population sizes. We monitored chorus activity in two populations of the European tree frog (Hyla arborea) over three years, while simultaneously conducting a capture-mark-recapture (CMR) study on breeding males. Three to four capture sessions were made each year, spread across the acme of the breeding season. Individual recognition was ensured by photographs of the linea marginalis. We used Pollock's robust design to test several biological hypotheses and estimate demographic parameters. Male survival was estimated as mean ±SE = 0.297 ± 0.154. Population trends deduced from chorus counts (maximum or mean) and modelled male population sizes were not concordant. We showed that there is no simple relationship between maximum or mean chorus size and modelled male population sizes estimated from CMR study and that population trends inferred from chorus counts are likely to be biased to an unknown extent. Even though CMR methods need significant time and personnel investments in order to produce reliable results, we advocate their use in the study of pond breeding amphibians' demography, as it provides unbiased and more precise estimates.
Hierarchical competition in pond-breeding anuran larvae in a Mediterranean area
Authors: Richter-Boix Alex , Llorente Gustavo , Montori Albert
Published: March 2007

The anuran larval guild is frequently characterised by the co-occurrence, with high niche overlap, of distinct species in the same pond at variables densities during development. Anuran larvae have therefore been widely studied as a model system for competition. Body size and activity level are considered the most important factors that influence the outcome of competition between tadpoles. As species from temporary ponds normally show higher activity levels in order to achieve rapid growth and thus reduce the risk of desiccation, these species are often considered superior competitors. We designed several laboratory experiments to examine the intra- and interspecific effects on growth rate, mass at metamorphosis and survival to metamorphosis of six species in a Mediterranean area. Body size and activity level were used as explanatory covariables to determine competitive ability among species. An asymmetric and hierarchical relationship was found among the six species. Larger tadpole species were more successful in competitive interactions than smaller ones, but no relationship was found between activity level and competition effects. Species typically found in temporary ponds (Pelodytes punctatus and Bufo calamita) were considered poor competitors in contrast with other communities studied. Species with low competitive ability can persist by using refuges in which competition is reduced (e.g. ephemeral ponds).
Annexin II expressed by osteoblasts and endothelial cells regulates stem cell adhesion, homing, and engraftment following transplantation
Authors: Jung Younghun , Wang Jingcheng , Song Junhui , Shiozawa Yusuke , Wang Jianhua , Havens Aaron , Wang Zhuo , Sun Yan-Xi , Emerson Stephen G. , Krebsbach Paul H. , Taichman Russell S.
Published: March 2007

Differentiation of hematopoietic stem cells (HSCs) after birth is largely restricted to the bone marrow cavity, where HSCs are associated closely with osteoblasts (OBs). How OBs localize HSCs to the endosteal niche remains unclear. To explore adhesive interactions between HSCs and OBs, a cell blot analysis was used that revealed 2 major bands that corresponded to monomers and multimers of annexin II (Anxa2). Immunohistochemistry revealed that OBs and marrow endothelial cells express Anxa2 at high levels. Function-blocking studies confirmed that Anxa2 mediates HSC adhesion mainly via the N-terminal portion of the Anxa2 peptide. Adhesion of HSCs to OBs derived from Anxa2-deficient animals (Anxa2−/−) was significantly impaired compared with OBs obtained from wild-type animals (Anxa2+/+). Moreover, fewer HSCs were found in the marrow of Anxa2−/− versus Anxa2+/+ animals. Short-term lodging, engraftment, and survival of irradiated mice with whole marrow cells were substantially inhibited by N-terminal peptide fragments of Anxa2 or anti-Anxa2 antibodies. Similar findings were noted in long-term competitive repopulation studies. Collectively, these findings reveal that Anxa2 regulates HSC homing and binding to the bone marrow microenvironment and suggest that Anxa2 is crucial for determining the bone marrow niche of HSCs.
The in vivo function of a noncanonical TRAF2-binding domain in the C-terminus of CD40 in driving B-cell growth and differentiation
Authors: Lu Li-Fan , Ahonen Cory L. , Lind Evan F. , Raman Vanitha S. , Cook W. James , Lin Ling-Li , Noelle Randolph J.
Published: March 2007

The recruitment of tumor necrosis factor receptor–associated factors (TRAFs) 1, 2, 3, 5, and 6 to the CD40 cytoplasmic tail upon CD40 trimerization results in downstream signaling events that ultimately lead to CD40-dependent, thymus-dependent (TD) humoral immune responses. Previously, we have shown signaling through the C-terminal tail of CD40 in the absence of canonical TRAF-binding sites is capable of signaling through an alternative TRAF2-binding site. Here, we demonstrate that B cells from mice harboring CD40 with only the C-terminal tail can activate both canonical and noncanonical NFκB signaling pathways. Moreover, while lacking germinal center formation, several hallmarks of humoral immune responses including clonal B-cell activation/expansion, antibody isotype switching, and affinity maturation remain normal. This study demonstrates a new functional domain in CD40 that controls critical aspects of B-cell immunity in an in vivo setting.
Forced expression of Nanog in hematopoietic stem cells results in a γδT-cell disorder
Authors: Tanaka Yosuke , Era Takumi , Nishikawa Shin-ichi , Kawamata Shin
Published: March 2007

Nanog is a key molecule involved in the maintenance of the self-renewal of undifferentiated embryonic stem (ES) cells. In this work we investigate whether Nanog can enhance self-renewal in hematopoietic stem cells. Contrary to our expectation, no positive effect of Nanog transduction was detected in bone marrow reconstitution assays. However, recipients of Nanog-transduced (Nanog) hematopoietic stem cells (HSCs) invariantly develop a unique disorder typified by an atrophic thymus occupied by Nanog-expressing γδT-cell receptor–positive (TCR+) cells (Nanog T cells). All thymi are eventually occupied by Nanog T cells with CD25+CD44+ surface phenotype that home selectively to the thymus on transfer and suppress normal thymocyte development, which is partly ascribed to destruction of the microenvironment in the thymus cortex. Moreover, this initial disorder invariantly develops to a lymphoproliferative disorder, in which Nanog T cells undergo unlimited proliferation in the peripheral lymphoid tissues and eventually kill the host. This invariable end result suggests that Nanog is a candidate oncogene for γδT-cell malignancy.
A novel fusion of RBM6 to CSF1R in acute megakaryoblastic leukemia
Authors: Gu Ting-lei , Mercher Thomas , Tyner Jeffrey W. , Goss Valerie L. , Walters Denise K. , Cornejo Melanie G. , Reeves Cynthia , Popova Lana , Lee Kimberly , Heinrich Michael C. , Rush John , Daibata Masanori , Miyoshi Isao , Gilliland D. Gary , Druker Brian J. , Polakiewicz Roberto D.
Published: March 2007

Activated tyrosine kinases have been frequently implicated in the pathogenesis of cancer, including acute myeloid leukemia (AML), and are validated targets for therapeutic intervention with small-molecule kinase inhibitors. To identify novel activated tyrosine kinases in AML, we used a discovery platform consisting of immunoaffinity profiling coupled to mass spectrometry that identifies large numbers of tyrosine-phosphorylated proteins, including active kinases. This method revealed the presence of an activated colony-stimulating factor 1 receptor (CSF1R) kinase in the acute megakaryoblastic leukemia (AMKL) cell line MKPL-1. Further studies using siRNA and a small-molecule inhibitor showed that CSF1R is essential for the growth and survival of MKPL-1 cells. DNA sequence analysis of cDNA generated by 5′RACE from CSF1R coding sequences identified a novel fusion of the RNA binding motif 6 (RBM6) gene to CSF1R gene generated presumably by a t(3;5)(p21;q33) translocation. Expression of the RBM6-CSF1R fusion protein conferred interleukin-3 (IL-3)–independent growth in BaF3 cells, and induces a myeloid proliferative disease (MPD) with features of megakaryoblastic leukemia in a murine transplant model. These findings identify a novel potential therapeutic target in leukemogenesis, and demonstrate the utility of phosphoproteomic strategies for discovery of tyrosine kinase alleles.
A thrombolytic regimen for high-risk deep venous thrombosis may substantially reduce the risk of postthrombotic syndrome in children
Authors: Goldenberg Neil A. , Durham Janette D. , Knapp-Clevenger R. , Manco-Johnson Marilyn J.
Published: March 2007

Important predictors of adverse outcomes of thrombosis in children, including postthrombotic syndrome (PTS), have recently been identified. Given this knowledge and the encouraging preliminary pediatric experience with systemic thrombolysis, we sought to retrospectively analyze our institutional experience with a thrombolytic regimen versus standard anticoagulation for acute, occlusive deep venous thrombosis (DVT) of the proximal lower extremities in children in whom plasma factor VIII activity and/or D-dimer concentration were elevated at diagnosis, from within a longitudinal pediatric cohort. Nine children who underwent the thrombolytic regimen and 13 who received standard anticoagulation alone were followed from time of diagnosis with serial clinical evaluation and standardized PTS outcome assessments conducted in uniform fashion. The thrombolytic regimen was associated with a markedly decreased odds of PTS at 18 to 24 months compared with standard anticoagulation alone, which persisted after adjustment for significant covariates of age and lag time to therapy (odds ratio [OR] = 0.018, 95% confidence interval [CI] = < 0.001-0.483; P = .02). Major bleeding developed in 1 child, clinically judged as not directly related to thrombolysis for DVT. These findings suggest that the use of a thrombolysis regimen may safely and substantially reduce the risk of PTS in children with occlusive lower-extremity acute DVT, providing the basis for a future clinical trial.
Leukemic blasts in transformed JAK2-V617F–positive myeloproliferative disorders are frequently negative for the JAK2-V617F mutation.
Authors: Theocharides Alexandre , Boissinot Marjorie , Girodon François , Garand Richard , Teo Soon-Siong , Lippert Eric , Talmant Pascaline , Tichelli Andre , Hermouet Sylvie , Skoda Radek C.
Published: March 2007

To study the role of the JAK2-V617F mutation in leukemic transformation, we examined 27 patients with myeloproliferative disorders (MPDs) who transformed to acute myeloid leukemia (AML). At MPD diagnosis, JAK2-V617F was detectable in 17 of 27 patients. Surprisingly, only 5 of 17 patients developed JAK2-V617F–positive AML, whereas 9 of 17 patients transformed to JAK2-V617F–negative AML. Microsatellite analysis in a female patient showed that mitotic recombination was not responsible for the transition from JAK2-V617F–positive MPD to JAK2-V617F–negative AML, and clonality determined by the MPP1 polymorphism demonstrated that the granulocytes and leukemic blasts inactivated the same parental X chromosome. In a second patient positive for JAK2-V617F at transformation, but with JAK2-V617F–negative leukemic blasts, we found del(11q) in all cells examined, suggesting a common clonal origin of MPD and AML. We conclude that JAK2-V617F–positive MPD frequently yields JAK2-V617F–negative AML, and transformation of a common JAK2-V617F–negative ancestor represents a possible mechanism.
Sleep apnoea in heart failure
Authors: Schulz R. , Blau A. , Börgel J. , Duchna H. W. , Fietze I. , Koper I. , Prenzel R. , Schädlich S. , Schmitt J. , Tasci S. , Andreas S.
Published: March 2007

Studies from the USA have reported that sleep apnoea is common in congestive heart failure (CHF), with Cheyne–Stokes respiration (CSR) being the most frequent type of sleep-disordered breathing (SDB) in these patients. Within the present study, the authors sought to assess the prevalence and type of SDB among CHF patients in Germany.

A total of 203 CHF patients participated in this prospective multicentre study. All patients were stable in New York Heart Association classes II and III and had a left ventricular ejection fraction (LVEF) <40%. The patients were investigated by polygraphy and all data were centrally analysed. Patient enrolment was irrespective of sleep-related symptoms.

The majority of patients were male with a mean age of 65 yrs and hospitalised. Of the 203 patients, 145 (71%) had an apnoea/hypopnoea index >10·h−1, obstructive sleep apnoea (OSA) occurred in 43% (n = 88) and CSR in 28% (n = 57) of patients.

The prevalence of sleep-disordered breathing is high in patients with stable severe congestive heart failure from a European population. As sleep-disordered breathing may have a negative impact on the prognosis of congestive heart failure, a sleep study should be performed in every patient with congestive heart failure and a left ventricular ejection fraction of <40%. This diagnostic approach should probably be adopted for all of these patients irrespective of the presence of sleep-related symptoms.
Remission of asthma: a prospective longitudinal study from northern Europe (RHINE study)
Authors: Holm M. , Omenaas E. , Gíslason T. , Svanes C. , Jögi R. , Norrman E. , Janson C. , Torén K.
Published: March 2007

The aim of the present study was to investigate the remission rate of adult asthma in a general population sample in relation to age, sex, asthma symptoms, allergic rhinitis and smoking.

A follow-up of the random population samples from the European Community Respiratory Health Survey in Northern Europe was conducted from 1999–2001 on 1,153 individuals (aged 26–53 yrs) with reported asthma. Remission was defined as no asthmatic symptoms in two consecutive years and no current use of asthma medication. Remission rates per 1,000 person-yrs were calculated and Cox regression models, adjusting for confounders, were used to estimate hazard ratios (HR) with 95% confidence intervals (CI).

An average remission rate of 20.2 per 1,000 person-yrs was found. There was no significant difference according to sex; the remission rates were 21.7 and 17.8 per 1,000 person-yrs in females and males, respectively. An increased remission rate was observed among subjects who quit smoking during the observation period. Subjects not reporting any asthma symptom at baseline had an increased remission rate. In the Cox regression model, ex-smoking (HR 1.65, 95% CI 1.01–2.71) was associated with increased remission rate, and reporting any asthma symptom at baseline was associated with decreased remission rate (HR 0.7, 95% CI 0.40–0.90).

In conclusion, the present prospective longitudinal study showed that quitting smoking and the presence of mild disease appeared to favour remission.
Role of IRAK4 and IRF3 in the control of intracellular infection withChlamydia pneumoniae
Authors: Trumstedt Christian , Eriksson Emma , Lundberg Anna M , Yang Tang-bin , Yan Zhong-qun , Wigzell Hans , Rottenberg Martin E
Published: March 2007

TLR signal transduction involves a MyD88-mediated pathway, which leads to recruitment of the IL-1 receptor (IL-1R)-associated kinase 4 (IRAK4) and Toll/IL-1R translation initiation region domain-containing adaptor-inducing IFN-β-mediated pathway, resulting in the activation of IFN regulatory factor (IRF)3. Both pathways can lead to expression of IFN-β. TLR-dependent and -independent signals converge in the TNF receptor-associated factor 6 (TRAF6) adaptor, which mediates the activation of NF-κΒ. Infection of murine bone marrow-derived macrophages (BMM) with Chlamydia pneumoniae induces IFN-α/β- and NF-κΒ-dependent expression of IFN-γ, which in turn, will control bacterial growth. The role of IRAK4 and IRF3 in the regulation of IFN-α/β expression and NF-κΒ activation was studied in C. pneumoniae-infected BMM. We found that levels of IFN-α, IFN-β, and IFN-γ mRNA were reduced in infected IRAK4−/− BMM compared with wild-type (WT) controls. BMM also showed an IRAK4-dependent growth control of C. pneumoniae. No increased IRF3 activation was detected in C. pneumoniae-infected BMM. Similar numbers of intracellular bacteria, IFN-α, and IFN-γ mRNA titers were observed in C. pneumoniae-infected IRF3−/− BMM. On the contrary, IFN-β−/− BMM showed lower IFN-α and IFN-γ mRNA levels and higher bacterial titers compared with WT controls. C. pneumoniae infection-induced activation of NF-κΒ and expression of proinflammatory cytokines were shown to be TRAF6-dependent but did not require IRAK4 or IRF3. Thus, our data indicate that IRAK4, but not IRF3, controls C. pneumoniae-induced IFN-α and IFN-γ secretion and bacterial growth. IRAK4 and IRF3 are redundant for infection-induced NF-κB activation, which is regulated by TRAF6.
Tombola, a tesmin/TSO1-family protein, regulates transcriptional activation in theDrosophilamale germline and physically interacts with Always early
Authors: Jiang Jianqiao , Benson Elizabeth , Bausek Nina , Doggett Karen , White-Cooper Helen
Published: March 2007

During male gametogenesis, a developmentally regulated and cell type-specific transcriptional programme is activated in primary spermatocytes to prepare for differentiation of sperm. The Drosophila aly-class meiotic-arrest loci (aly, comr, achi/vis and topi)are essential for activation of transcription of many differentiation-specific genes, and several genes important for meiotic cell cycle progression, thus linking meiotic divisions to cellular differentiation during spermatogenesis. Protein interaction studies suggest that the aly-class gene products form a chromatin-associated complex in primary spermatocytes. We identify,clone and characterise a new aly-class meiotic-arrest gene, tombola (tomb), which encodes a testis-specific CXC-domain protein that interacts with Aly. The tomb mutant phenotype is more like that of aly and comr mutants than that of achi/vis or topi mutants in terms of target gene profile and chromosome morphology. tomb encodes a chromatin-associated protein required for localisation of Aly and Comr, but not Topi, to chromatin Reciprocally, aly and comr, but not topi or achi/vis, are required to maintain the normal localisation of Tomb. tomb and aly might be components of a complex paralogous to the Drosophila dREAM/Myb-MuvB and C. elegans DRM transcriptional regulatory complexes.
Activities of N-Myc in the developing limb link control of skeletal size with digit separation
Authors: Ota Sara , Zhou Zi-Qiang , Keene Doug R. , Knoepfler Paul , Hurlin Peter J.
Published: March 2007

The developing limb serves as a paradigm for studying pattern formation and morphogenetic cell death. Here, we show that conditional deletion of N-Myc(Mycn) in the developing mouse limb leads to uniformly small skeletal elements and profound soft-tissue syndactyly. The small skeletal elements are associated with decreased proliferation of limb bud mesenchyme and small cartilaginous condensations, and syndactyly is associated with a complete absence of interdigital cell death. Although Myc family proteins have pro-apoptotic activity, N-Myc is not expressed in interdigital cells undergoing programmed cell death. We provide evidence indicating that the lack of interdigital cell death and associated syndactyly is related to an absence of interdigital cells marked by expression of Fgfr2 and Msx2. Thus, instead of directly regulating interdigital cell death, we propose that N-Myc is required for the proper generation of undifferentiated mesenchymal cells that become localized to interdigital regions and trigger digit separation when eliminated by programmed cell death. Our results provide new insight into mechanisms that control limb development and suggest that defects in the formation of N-Myc-dependent interdigital tissue may be a root cause of common syndromic forms of syndactyly.
The negative regulation of Mesp2 by mouse Ripply2 is required to establish the rostro-caudal patterning within a somite
Authors: Morimoto Mitsuru , Sasaki Nobuo , Oginuma Masayuki , Kiso Makoto , Igarashi Katsuhide , Aizaki Ken-ichi , Kanno Jun , Saga Yumiko
Published: March 2007

The Mesp2 transcription factor plays essential roles in segmental border formation and in the establishment of rostro-caudal patterning within a somite. A possible Mesp2 target gene, Ripply2, was identified by microarray as being downregulated in the Mesp2-null mouse. Ripply2 encodes a putative transcriptional co-repressor containing a WRPW motif. We find that Mesp2 binds to the Ripply2 gene enhancer,indicating that Ripply2 is a direct target of Mesp2. We then examined whether Ripply2 is responsible for the repression of genes under the control of Mesp2 by generating a Ripply2-knockout mouse. Unexpectedly, Ripply2-null embryos show a rostralized phenotype, in contrast to Mesp2-null mice. Gene expression studies together with genetic analyses further revealed that Ripply2 is a negative regulator of Mesp2 and that the loss of the Ripply2 gene results in the prolonged expression of Mesp2, leading to a rostralized phenotype via the suppression of Notch signaling. Our study demonstrates that a Ripply2-Mesp2 negative-feedback loop is essential for the periodic generation of the rostro-caudal polarity within a somite.
Soma-dependent modulations contribute to divergence ofrhomboidexpression during evolution ofDrosophilaeggshell morphology
Authors: Nakamura Yukio , Kagesawa Tatsuo , Nishikawa Minori , Hayashi Yoshiki , Kobayashi Satoru , Niimi Teruyuki , Matsuno Kenji
Published: March 2007

Patterning of the respiratory dorsal appendages (DAs) on the Drosophila melanogaster eggshell is tightly regulated by epidermal growth factor receptor (EGFR) signaling. Variation in the DA number is observed among Drosophila species; D. melanogaster has two DAs and D. virilis has four. Diversification in the expression pattern of rhomboid (rho), which activates EGFR signaling in somatic follicle cells, could cause the evolutionary divergence of DA numbers. Here we identified a cis-regulatory element of D. virilis rho. A comparison with D. melanogaster rho enhancer and activity studies in homologous and heterologous species suggested that these rho enhancers did not functionally diverge significantly during the evolution of these species. Experiments using chimeric eggs composed of a D. virilis oocyte and D. melanogaster follicle cells showed the evolution of DA number was not attributable to germline Gurken (Grk) signaling, but to divergence in events downstream of Grk signaling affecting the rho enhancer activity in somatic follicle cells. We found that a transcription factor,Mirror, which activates rho, could be one of these downstream factors. Thus, evolution of the trans-regulatory environment that controls rho expression in somatic follicle cells could be a major contributor to the evolutionary changes in DA number.
The chromatin remodeler Mi-2β is required for establishment of the basal epidermis and normal differentiation of its progeny
Authors: Kashiwagi Mariko , Morgan Bruce A. , Georgopoulos Katia
Published: March 2007

Using conditional gene targeting in mice, we show that the chromatin remodeler Mi-2β is crucial for different aspects of skin development. Early (E10.5) depletion of Mi-2β in the developing ventral epidermis results in the delayed reduction of its suprabasal layers in late embryogenesis and to the ultimate depletion of its basal layer. Later (E13.5)loss of Mi-2β in the dorsal epidermis does not interfere with suprabasal layer differentiation or maintenance of the basal layer, but induction of hair follicles is blocked. After initiation of the follicle, some subsequent morphogenesis of the hair peg may proceed in the absence of Mi-2β, but production of the progenitors that give rise to the inner layers of the hair follicle and hair shaft is impaired. These results suggest that the extended self-renewal capacity of epidermal precursors arises early during embryogenesis by a process that is critically dependent on Mi-2β. Once this process is complete, Mi-2β is apparently dispensable for the maintenance of established repopulating epidermal stem cells and for the differentiation of their progeny into interfollicular epidermis for the remainder of gestation. Mi-2β is however essential for the reprogramming of basal cells to the follicular and, subsequently, hair matrix fates.
Translational control of maternalCyclin BmRNA by Nanos in theDrosophilagermline
Authors: Kadyrova Lyudmila Y. , Habara Yasuaki , Lee Tammy H. , Wharton Robin P.
Published: March 2007

In the Drosophila embryo, Nanos and Pumilio collaborate to repress the translation of hunchback mRNA in the somatic cytoplasm. Both proteins are also required for repression of maternal Cyclin B mRNA in the germline; it has not been clear whether they act directly on Cyclin B mRNA, and if so, whether regulation in the presumptive somatic and germline cytoplasm proceeds by similar or fundamentally different mechanisms. In this report, we show that Pumilio and Nanos bind to an element in the 3′ UTR to repress Cyclin B mRNA. Regulation of Cyclin B and hunchback differ in two significant respects. First,Pumilio is dispensable for repression of Cyclin B (but not hunchback) if Nanos is tethered via an exogenous RNA-binding domain. Nanos probably acts, at least in part, by recruiting the CCR4-Pop2-NOT deadenylase complex, interacting directly with the NOT4 subunit. Second,although Nanos is the sole spatially limiting factor for regulation of hunchback, regulation of Cyclin B requires another Oskar-dependent factor in addition to Nanos. Ectopic repression of Cyclin B in the presumptive somatic cytoplasm causes lethal nuclear division defects. We suggest that a requirement for two spatially restricted factors is a mechanism for ensuring that Cyclin B regulation is strictly limited to the germline.
Cell fate polarization in ascidian mesenchyme/muscle precursors by directed FGF signaling and role for an additional ectodermal FGF antagonizing signal in notochord/nerve cord precursors
Authors: Kim Gil Jung , Kumano Gaku , Nishida Hiroki
Published: March 2007

Asymmetric cell division plays a fundamental role in generating various types of embryonic cell. In ascidian embryos, asymmetric cell divisions occur in the vegetal hemisphere in a manner similar to those found in Caenorhabditis elegans. Early divisions in embryos of both species involve inductive events on a single mother cell that result in production of daughters with different cell fates. Here we show in the ascidian Halocynthia roretzi that polarity of muscle/mesenchyme mother precursors is determined solely by the direction from which the FGF9/16/20 signal is presented, a role similar to that of Wnt signaling in the EMS and T cell divisions in C. elegans. However, polarity of nerve cord/notochord mother precursors is determined by possible antagonistic action between the FGF signal and a signal from anterior ectoderm, providing a new mechanism underlying asymmetric cell division. The ectoderm signal suppresses MAPK activation and expression of Hr-FoxA, which encodes an intrinsic competence factor for notochord induction, in the nerve cord lineage.
Cytokine Profiling in Human Colostrum and Milk by Protein Array
Authors: Kverka Miloslav , Burianova Jaroslava , Lodinova-Zadnikova Raja , Kocourkova Ingrid , Cinova Jana , Tuckova Ludmila , Tlaskalova-Hogenova Helena
Published: March 2007

Background: Human colostrum and milk contain components that influence development. Our aim was to use a protein array to determine the cytokine profile of human lacteal secretions and changes that occur during the early postpartum period.

Methods: We collected 17 samples of colostrum during the first 2 days postpartum and a 2nd group of 5 sets of 2 to 3 sequential colostrum or milk samples (at 20- to 30-h intervals). We analyzed the samples with array membranes consisting of 42 or 79 antibodies directed against cytokines.

Results: In most samples, we detected the previously described cytokines interleukin-8 (IL-8)/CXCL8, epidermal growth factor (EGF), growth-related oncoprotein (GRO)/CXCL1–3, angiogenin, transforming growth factor β-2, and monocyte chemotactic protein 1 (MCP-1/CCL2). In addition, we found 32 cytokines that have not been described before in colostrum. Cytokine concentrations differed among mothers, and the spectrum of cytokines changed with time after delivery. A significant decrease occurred in IL-12 and macrophage inflammatory protein-1δ/CCL15 and a significant increase in MCP-1/CCL2. The production of angiogenin, vascular endothelial growth factor, GRO/CXCL1–3, EGF, and IL-8/CXCL8 remained high throughout. The concentrations of 2 selected cytokines measured with the array technique and ELISA showed moderate to strong correlation (r = 0.63 for EGF and r = 0.84 for IL-8/CXCL8).

Conclusion: Despite the lack of precise quantification, the protein array might be suitable for cytokine screening. It allows simultaneous detection of a broad spectrum of cytokines (including those not described before) in lacteal secretions.
Comparison of 11 Human Insulin Assays: Implications for Clinical Investigation and Research
Authors: Manley Susan E , Stratton Irene M , Clark Penelope M , Luzio Stephen D
Published: March 2007

Background: The American Diabetes Association task force on standardization of insulin assays in 1996 showed wide variation in assay bias. Newer assays are specific for insulin, with several now available on automated immunoassay analyzers.

Methods: In 2004, we compared 11 commercially available insulin assays by analyzing 150 serum samples (99 fasting/51 postprandial) from study participants with various degrees of glucose intolerance (exclusions being type 1 diabetes, insulin treatment, or presence of insulin antibodies). All assays were calibrated against International Reference Preparation 66/304. One assay was not specific for insulin and another was an RIA; 10 assays used enzyme/chemiluminescent labels. Bland–Altman difference plots were modified to use the mean insulin from all assays on the x-axis as a common comparator.

Results: As in the 1996 study, insulin values from the different assays varied by a factor of 2, with the nonspecific assay ranking in the middle of the distribution. Spearman rank correlation coefficients, for ranking samples vs the mean, were 0.983–0.997. Both offsets and concentration-dependent differences were seen in the modified difference plots. Imprecision (mean CV) for automated assays (3%) was not significantly different from manual assays (5%). Similar values were obtained when one automated assay was run in laboratories in both the UK and the US. Results of 1 assay showed lower insulin concentrations in heparinized plasma than in serum.

Conclusions: Assay performance must be considered before comparing insulin results. The 2-fold variation in insulin results may be related to specificity, manufacturers’ calibration procedures or conversion factors.
Die Vertreibung der Kultur aus der Sprache. 13 Reflexionen zu einem reflexionsresistenten Thema / Banishing culture from language
Authors: Ehlich Konrad
Published: March 2007

The relationship between language studies and cultural studies to one another is of a highly problematic character – if there is any such interrelationship at all. At first sight, such a situation may appear strange but a closer look reveals that there are deeply rooted reasons for this reciprocal indifference, reasons that are quite complex in nature. The paper has the intention to clarify some of them, in the hope that it may contribute to a more complex and, thus, a more adequate theoretical framework from which insight into language and insight into culture might ensue.