Ensemble Prediction of a Halo Coronal Mass Ejection Using Heliospheric Imagers.

The Solar TErrestrial RElations Observatory (STEREO) and its heliospheric imagers (HIs) have provided us the possibility to enhance our understanding of the interplanetary propagation of coronal mass ejections (CMEs). HI-based methods are able to forecast arrival times and speeds at any target and use the advantage of tracing a CME's path of propagation up to 1 AU and beyond. In our study, we use the ELEvoHI model for CME arrival prediction together with an ensemble approach to derive uncertainties in the modeled arrival time and impact speed. The CME from 3 November 2010 is analyzed by performing 339 model runs that are compared to in situ measurements from lined-up spacecraft MErcury Surface, Space ENvironment, GEochemistry, and Ranging and STEREO-B. Remote data from STEREO-B showed the CME as halo event, which is comparable to an HI observer situated at L1 and observing an Earth-directed CME. A promising and easy approach is found by using the frequency distributions of four ELEvoHI output parameters, drag parameter, background solar wind speed, initial distance, and speed. In this case study, the most frequent values of these outputs lead to the predictions with the smallest errors. Restricting the ensemble to those runs, we are able to reduce the mean absolute arrival time error from 3.5 ± 2.6 to 1.6 ± 1.1 hr at 1 AU. Our study suggests that L1 may provide a sufficient vantage point for an Earth-directed CME, when observed by HI, and that ensemble modeling could be a feasible approach to use ELEvoHI operationally.

Modeling observations of solar coronal mass ejections with heliospheric imagers verified with the Heliophysics System Observatory.

We present an advance toward accurately predicting the arrivals of coronal mass ejections (CMEs) at the terrestrial planets, including Earth. For the first time, we are able to assess a CME prediction model using data over two thirds of a solar cycle of observations with the Heliophysics System Observatory. We validate modeling results of 1337 CMEs observed with the Solar Terrestrial Relations Observatory (STEREO) heliospheric imagers (HI) (science data) from 8 years of observations by five in situ observing spacecraft. We use the self-similar expansion model for CME fronts assuming 60° longitudinal width, constant speed, and constant propagation direction. With these assumptions we find that 23%-35% of all CMEs that were predicted to hit a certain spacecraft lead to clear in situ signatures, so that for one correct prediction, two to three false alarms would have been issued. In addition, we find that the prediction accuracy does not degrade with the HI longitudinal separation from Earth. Predicted arrival times are on average within 2.6 ± 16.6 h difference of the in situ arrival time, similar to analytical and numerical modeling, and a true skill statistic of 0.21. We also discuss various factors that may improve the accuracy of space weather forecasting using wide-angle heliospheric imager observations. These results form a first-order approximated baseline of the prediction accuracy that is possible with HI and other methods used for data by an operational space weather mission at the Sun-Earth L5 point.

The sociopolitical in human genetics education.

Education must go beyond only countering essentialist and deterministic views of genetics.

Writhed Analytical Magnetic Flux Rope Model.

Observations of magnetic clouds, within interplanetary coronal mass ejections (ICMEs), are often well described by flux rope models. Most of these assume either a cylindrical or toroidal geometry. In some cases, these models are also capable of accounting for non-axisymmetric cross-sections but they generally all assume axial invariance. It can be expected that any ICME, and its flux rope, will be deformed along its axis due to influences such as the solar wind. In this work, we aim to develop a writhed analytical magnetic flux rope model which would allow us to analytically describe a flux rope structure with varying curvature and torsion so that we are no longer constrained to a cylindrical or toroidal geometry. In this first iteration of our model we will solely focus on a circular cross-section of constant size. We describe our flux rope geometry in terms of a parametrized flux rope axis and a parallel transport frame. We derive expressions for the axial and poloidal magnetic field components under the assumption that the total axial magnetic flux is conserved. We find an entire class of possible solutions, which differ by the choice of integration constants, and present the results for a specific example. In general, we find that the twist of the magnetic field locally changes when the geometry deviates from a cylinder or torus. This new approach also allows us to generate completely new types of in situ magnetic field profiles which strongly deviate from those generated by cylindrical or toroidal models.

Protein phosphatase 2B (PP2B, calcineurin) in Paramecium: partial characterization reveals that two members of the unusually large catalytic subunit family have distinct roles in calcium-dependent processes.

We characterized the calcineurin (CaN) gene family, including the subunits CaNA and CaNB, based upon sequence information obtained from the Paramecium genome project. Paramecium tetraurelia has seven subfamilies of the catalytic CaNA subunit and one subfamily of the regulatory CaNB subunit, with each subfamily having two members of considerable identity on the amino acid level (>or=55% between subfamilies, >or=94% within CaNA subfamilies, and full identity in the CaNB subfamily). Within CaNA subfamily members, the catalytic domain and the CaNB binding region are highly conserved and molecular modeling revealed a three-dimensional structure almost identical to a human ortholog. At 14 members, the size of the CaNA family is unprecedented, and we hypothesized that the different CaNA subfamily members were not strictly redundant and that at least some fulfill different roles in the cell. This was tested by selecting two phylogenetically distinct members of this large family for posttranscriptional silencing by RNA interference. The two targets resulted in differing effects in exocytosis, calcium dynamics, and backward swimming behavior that supported our hypothesis that the large, highly conserved CaNA family members are not strictly redundant and that at least two members have evolved diverse but overlapping functions. In sum, the occurrence of CaN in Paramecium spp., although disputed in the past, has been established on a molecular level. Its role in exocytosis and ciliary beat regulation in a protozoan, as well as in more complex organisms, suggests that these roles for CaN were acquired early in the evolution of this protein family.

[Report from the Committee for Advanced Therapies (CAT). Pitfalls on the way from concept to medical treatment with advanced therapy medicinal products]. / Erfahrungsbericht aus dem Ausschuss für neuartige Therapien (CAT). Fallstricke auf dem Weg vom Konzept zur medizinischen Anwendung neuartiger Therapien.

Advanced therapy medicinal products (ATMP) are highly innovative and complex medicines. They comprise gene therapy medicinal products, somatic cell therapy medicinal products, and tissue-engineered products (TEP). With the European Regulation on ATMP that came into force in 2008, a consolidated regulatory framework was created, where the Committee for Advanced Therapies (CAT) at the European Medicines Agency (EMA) plays a central role. This article discusses pitfalls and challenges that the CAT has experienced in its discussions of various procedures. Often ATMPs are developed by small and medium-sized enterprises (SME) which also face nonscientific challenges. The CAT wishes to meet these challenges on a scientific and regulatory level during its 2010-2015 work program.

Peritonsillar abscess: is there any evidence of lateralized distribution? An analysis of 294 patients.

OBJECTIVE: Generally, peritonsillar abscess (PTA) occurs only on one side. Diseases of paired organs show a distinct asymmetry of occurrence: for instance gynaecomastia, varicocele, trigeminal neuralgia, carcinoma of the breast and carcinoma of the ethmoid sinus. Therefore, the goal of the present study was to investigate a possible dominance of one side in PTA. MATERIAL AND METHOD: Lateralization of a PTA was studied in 294 patients treated at Radebeul Hospital between January 2004 and December 2009. RESULT: We found only a slight predominance of the left side in male as well as female patients. CONCLUSION: The cause of the slight asymmetry is unclear. It is also possible that the non significant dominance is coincidental.

Identification and characterization of an escorter for two secretory adhesins in Toxoplasma gondii.

The intracellular protozoan parasite Toxoplasma gondii shares with other members of the Apicomplexa a common set of apical structures involved in host cell invasion. Micronemes are apical secretory organelles releasing their contents upon contact with host cells. We have identified a transmembrane micronemal protein MIC6, which functions as an escorter for the accurate targeting of two soluble proteins MIC1 and MIC4 to the micronemes. Disruption of MIC1, MIC4, and MIC6 genes allowed us to precisely dissect their contribution in sorting processes. We have mapped domains on these proteins that determine complex formation and targeting to the organelle. MIC6 carries a sorting signal(s) in its cytoplasmic tail whereas its association with MIC1 involves a lumenal EGF-like domain. MIC4 binds directly to MIC1 and behaves as a passive cargo molecule. In contrast, MIC1 is linked to a quality control system and is absolutely required for the complex to leave the early compartments of the secretory pathway. MIC1 and MIC4 bind to host cells, and the existence of such a complex provides a plausible mechanism explaining how soluble adhesins act. We hypothesize that during invasion, MIC6 along with adhesins establishes a bridge between the host cell and the parasite.

Dehydropolymerisation of methylamine borane using a dinuclear 1,3-allenediyl bridged zirconocene complex.

The dinuclear zirconocene chloride complex 1 is a highly active precatalyst for the dehydropolymerisation of methylamine borane. Comparison with mononuclear Zr chlorides and related dinuclear complexes suggests that the nature of the bridging motif is essential for the unique reactivity of 1.

Differences in oxygen metabolism of phagocytosing monocytes and neutrophils.

The oxidative metabolism of monocytes and polymorphonuclear leukocytes from human peripheral blood was studied in resting and phagocytosing cells. Monocytes, like neutrophils, showed an increase in oxygen consumption during phagocytosis with a concurrent release of superoxide anions and hydrogen peroxide. Both oxygen products are highly reactive agents with potential bactericidal activity. Neutrophils consumed two and a half times as much oxygen, generated about twice as much superoxide, and released five times as much hydrogen peroxide as monocytes did. Monocytes generated superoxide and hydrogen peroxide at equivalent rates.Antimycin A, a specific mitochondrial respiratory chain inhibitor, depressed the oxygen consumption of monocytes by congruent with70% but had no effect on neutrophil respiration. Therefore, the oxygen consumed by phagocytosing monocytes appeared to be metabolized in two distinct processes: congruent with30% of the oxygen is converted to hydrogen peroxide, whereas the remaining 70% is metabolized via the mitochondrial respiratory chain. The release of superoxide and hydrogen peroxide was unaffected by antimycin in either cell type. Phagocytosis of zymosan particles by monocytes was nearly abolished by antimycin, whereas no effect was noted with neutrophils. Thus, phagocytosis appears to be highly dependent on oxidative phosphorylation in monocytes but not in polymorphonuclear leukocytes. Moreover, in monocytes treated with antimycin, an addition of opsonized zymosan particles induced stimulation of the oxidative metabolism without occurrence of ingestion.

Modulation of the terminal differentiation of human squamous carcinoma cells in vitro by all-trans-retinoic acid.

A malignant human cell line (SqCC/Y1) derived from a squamous carcinoma of the buccal mucosa is described. It formed a stratified cellular structure with ultrastructural characteristics of a fully differentiated stratified squamous epithelium when cultured in equal parts of Dulbecco's modified Eagle medium and Ham's medium F12, supplemented only with insulin, transferrin, and selenium. After 14 days in culture in this defined medium, 30% of the cells became keratinized (insoluble in detergent), and 75% of the cells were capable of being induced to form cornified cell envelopes. Involucrin, the precursor protein of the cornified cell envelope, could be detected by immunofluorescence only in suprabasal cells. Treatment of SqCC/Y1 cultures with 5 X 10(-8) M all-trans-retinoic acid (RA) completely inhibited stratification and markedly increased cell desquamation. In the presence of RA, less than 10% of the cells became keratinized, and only 15-20% of the cells acquired envelope-forming competence. The fraction of colony-forming cells in RA-treated cultures was tenfold higher than in fully mature cultures. Thus RA appears to be an effective inhibitor of terminal differentiation of SqCC/Y1 cells.

Regulation of growth and differentiation of human keratinocytes by type beta transforming growth factor and epidermal growth factor.

The role of type beta transforming growth factor (TGF beta) and epidermal growth factor (EGF) as regulators of the growth and differentiation of cultured human neonatal epidermal cells and squamous carcinoma cells was investigated in postconfluent cultures. Neither cell proliferation nor DNA synthesis was affected by treatment with TGF beta alone; however, EGF significantly stimulated cell growth, and this process was specifically antagonized by TGF beta. In addition, TGF beta inhibited the maturation of human foreskin-derived epidermal cells, as measured by their competence to synthesize involucrin and to form cornified cell envelopes, in a dose-dependent manner. Although treatment with EGF did not affect the maturation of human foreskin-derived epidermal cells, the combination of a low concentration of TGF beta with EGF resulted in significant enhancement of the maturation of these normal keratinocytes. Growth of three of four squamous carcinomas in the presence of EGF was not inhibited by TGF beta. In addition, all four carcinomas were either totally or partially resistant to the induction of maturation by the combination of TGF beta and EGF. This resistance of squamous carcinomas to TGF beta was paralleled by an increased sensitivity to the antikeratinizing effects of EGF. Thus, TGF beta inhibited the mitogenic stimulation of keratinocytes by EGF and induces cell maturation.

Mutant p53 tumor suppressor gene causes resistance to transforming growth factor beta 1 in murine keratinocytes.

Human carcinoma cell lines are frequently refractory to the antiproliferative effect of the autocrine growth inhibitor transforming growth factor beta 1 (TGF-beta 1) and often express mutant forms of the tumor suppressor gene p53. Therefore, we wished to determine whether mutant p53 affects the cellular response to TGF-beta 1. A murine p53 complementary DNA carrying an activating point mutation was introduced into TGF-beta 1-sensitive BALB/MK mouse epidermal keratinocytes by retroviral infection. Mp53 transformed cells displayed a spindle-type morphology and expressed between 0.02 and 0.7 ng of mutant p53/mg total protein. Furthermore, whereas TGF-beta 1 caused approximately 90% maximal inhibition of DNA synthesis of parental BALB/MK cells, the Mp53 transformants were inhibited by less than 70%. The median inhibiting dose of TGF-beta 1 was 4.07 +/- 1 (SE) pM for BALB/MK cells, but ranged from 2.4 to 11.2 pM and from 11.7 to 40 pM for two different sets of Mp53 transformants, and increased as a function of the amounts of mutant p53 protein that were expressed. Our findings suggest that mutant forms of p53 inhibit the antiproliferative effect of TGF-beta 1 by interfering with its signaling pathway.

Transforming growth factor beta type I receptor kinase mutant associated with metastatic breast cancer.

Malignant breast carcinoma cell lines are frequently refractory to transforming growth factor beta (TGF-beta)-mediated cell cycle arrest. To identify molecular mechanisms of TGF-beta resistance, we have conducted a comprehensive structural analysis of the TGF-beta receptor types I (TbetaR-I) and II (TbetaR-II) genes in primary human breast carcinomas and associated axillary lymph node metastases. No evidence for loss of expression (n=14) or structural alterations of the TbetaR-II gene (n=30) were identified. However, 2 of 31 primary carcinomas and 5 of 12 lymph node metastases carried a C to A transversion mutation resulting in a serine to tyrosine substitution at codon 387 (S387Y) of the TbetaR-I receptor gene. This TbetaR-I mutant has a diminished ability to mediate TGF-beta-dependent effects on gene expression as compared with wild-type TbetaR-I. S387Y is the first reported mutation in the TbetaR-I gene in human cancer that was primarily associated with lymph node metastases in the present series.

Constitutive expression of the c-fos protooncogene in murine keratinocytes: potentiation of the mitogenic response to insulin-like growth factor 1.

In order to determine the biological effects of activation of the c-fos protooncogene on growth and differentiation of BALB/MK mouse keratinocytes, these cells were transfected with the plasmid pMAN-fos, which encompasses the human c-fos coding region under transcriptional control of a mouse mammary tumor virus promoter, as well as the gene encoding neomycin phosphotransferase. Of approximately 70 individual clones obtained by selection in Geneticin, 5 clones that constitutively expressed c-fos mRNA as well as p55fos protein were selected for phenotypic analysis. Each of these clones displayed density-dependent growth arrest at confluency when deprived of serum and mitogens. DNA synthesis could be reinitiated in quiescent cultures by treatment with epidermal growth factor to a similar extent as in the parental line. In four of five fos transfectants, insulin-like growth factor 1 potentiated the mitogenic response to epidermal growth factor more than 10-fold, compared to only 2.5-fold in the parental cells. The enhanced response to insulin-like growth 1 could not be attributed to changes in the number or the affinity of receptors for the growth factor. Finally, the constitutive expression of c-fos did not interfere with the induction of terminal differentiation by calcium.

Reversible effects of retinoic acid on glycosaminoglycan synthesis during differentiation of HL-60 leukemia cells.

Glycosaminoglycans (GAGs) play an important role in cell-cell and cell-substratum interactions, and undergo specific changes during neutrophil development. Previous studies (Luikart, S.D., Maniglia, C. A., and Sartorelli, A. C. Cancer Res., 44: 2907-2912, 1984) have shown that both dimethyl sulfoxide and 4-beta-phorbol-12-beta-myristate-13-alpha-acetate decreased GAG production by a hypoxanthine-guanine phosphoribosyl transferase-deficient clone of HL-60 promyelocytic leukemia cells prior to the appearance of a mature myeloid or monocytoid phenotype. To expand these investigations further, GAGs were analyzed by cetylpyridinium chloride precipitation and DEAE-Sephacel ion-exchange chromatography after labeling of parental HL-60 cultures with [35S]sulfate and D-[3H]glucosamine for 6 h, following treatment with 1 microM all-trans retinoic acid (RA). Chondroitin sulfate represented the major GAG species produced, although endo-beta-galactosidase-sensitive undersulfated macromolecules which possibly might be keratan sulfate, were also identified. GAG production decreased over a time period of 144 h in culture. RA treatment reduced the amount of radiolabeled cell-associated GAGs by 50% after 48, 96, and 144 h of exposure. In contrast, commitment to myelocytic maturation of the majority (i.e., approximately 60%) of the cells occurred between 72 and 96 h of RA treatment. Concurrently with the appearance of mature granulocytic cells, two-thirds of the radiolabeled GAGs were recovered from the medium, compared to one-third in untreated cultures, a phenomenon that resulted in an overall alteration in the distribution of GAGs. When RA was removed by washing after either 48 h (i.e., precommitment to differentiation) or 96 h (i.e., postcommitment to differentiation), a 1.5- to 3.5-fold increase in GAG production was noted 48 h later; this increase was unrelated to the medium change or to alterations in cell cycle distribution. The amounts of endo-beta-galactosidase-sensitive macromolecules were unaltered. Thus, although 1 microM RA inhibited the synthesis of chondroitin sulfate by HL-60 leukemia cells, this inhibition was reversible by removal of the drug and appeared to be unrelated to the commitment to myelocytic maturation.

Activation of the autocrine transforming growth factor alpha pathway in human squamous carcinoma cells.

Transforming growth factor alpha is an autocrine mitogen for nonneoplastic keratinocytes, which exerts its function by binding to the receptor for epidermal growth factor. In order to determine whether this autocrine pathway is activated in squamous carcinoma cells, we analyzed the production of transforming growth factor alpha as well as the expression and regulation of epidermal growth factor receptors in a panel of human squamous carcinoma cell lines. Immunoreactive transforming growth factor alpha was detectable in squamous carcinoma cells as well as in quiescent nonneoplastic keratinocytes. However, in the absence of exogenous mitogens, only the squamous carcinoma cells secreted the growth factor into the medium, whereas untransformed keratinocytes did not. Each of the squamous carcinoma cell lines expressed significantly greater numbers of cell surface epidermal growth factor receptors than normal keratinocytes. The epidermal growth factor receptor gene was amplified and overexpressed in three of the squamous carcinoma cell lines (A431, CaSki, SqCC/Y1). Two of the squamous carcinoma cell lines (C4-1 and CE-48) displayed a relative inability to down-regulate epidermal growth factor receptors in response to epidermal growth factor. The mechanism of receptor overexpression in the remaining three cell lines (A253, CaLu-1, FaDu) is unexplained. Thus, human squamous carcinoma cell lines frequently exhibit a combination of the constitutive secretion of transforming growth factor alpha and the overexpression of epidermal growth factor receptors. Treatment of these tumor cells with an antibody directed against the ligand-binding domain of the epidermal growth factor receptor inhibited their growth by approximately 50%. These findings suggest that designing strategies to interrupt the transforming growth factor alpha autocrine pathway might lead to new modalities to treat this class of malignant tumors.

A mutation in the transforming growth factor beta type II receptor gene promoter associated with loss of gene expression.

Expression of transforming growth factor beta type II receptors (TbetaR-IIs) is either greatly decreased or absent in many tumors, implying that the loss of TbetaR-II function is one of the mechanisms leading to tumor development. In this report, we examine the expression of the TbetaR-II receptor in a squamous carcinoma cell line that expressed reduced levels of TbetaR-II mRNA. We found an A --> G mutation at position -364 of the 5' untranslated region of the TbetaR-II gene. This mutation results in significantly decreased transcriptional activity by the TbetaR-II gene promoter, suggesting that it is a primary mechanism of loss of TbetaR-II expression in this tumor cell line.

Bcl-2 antisense oligodeoxynucleotide therapy of Epstein-Barr virus-associated lymphoproliferative disease in severe combined immunodeficient mice.

Bcl-2 is upregulated by Epstein-Barr virus (EBV) in immortalized lymphoblastoid (LCL) B cells and is expressed in the majority of EBV-associated posttransplant lymphoproliferative disorders (PTLDs). Given the antiapoptotic function and chemoprotective effects of Bcl-2, it represents a rational target for modulation using antisense oligodeoxynucleotides in Bcl-2-expressing, EBV-associated lymphoproliferative disorders. Using a fully phosphorothioated oligodeoxynucleotide targeted to the first six codons of Bcl-2, we examined the effects of Bcl-2 antisense both in vitro in LCLs and in vivo in the human/severe combined immunodeficient chimeric model of EBV-associated lymphoproliferative disorders. In vitro treatment of LCLs with Bcl-2 antisense in the presence of cationic lipid was associated with decreased expression of Bcl-2 protein, inhibition of proliferation, and stimulation of apoptotic cell death; these effects were sequence-dependent. Furthermore, treatment of LCL-bearing severe combined immunodeficient mice with Bcl-2 antisense but not control oligodeoxynucleotides completely prevented or significantly delayed the development of fatal EBV-positive lymphoproliferative disease in vivo. These studies demonstrate that Bcl-2 antisense oligodeoxynucleotides mediate sequence-dependent antitumor effects in EBV-associated B-cell lymphoproliferations both in vitro and in vivo. These findings suggest that Bcl-2 antisense therapy may represent a novel antitumor treatment strategy for EBV-associated PTLDs and other Bel-2-expressing, EBV-positive malignancies.

Missense mutations of the transforming growth factor beta type II receptor in human head and neck squamous carcinoma cells.

In this study, we report the occurrence of missense mutations of the transforming growth factor beta (TGF beta) type II receptor gene in two human squamous head and neck carcinoma cell lines. Both mutations are G:C-->C:G transversions, which result in the replacement of a glutamic acid by a glutamine, and of an arginine by a proline residue, respectively. Moreover, both are located at highly conserved sites within the serine-threonine kinase domain. One of the mutants appears to be defective in its autophosphorylation as well as in the transphosphorylation of the TGF beta type 1 receptor protein, whereas the second mutant appears to be constitutively activated. These are the first reported naturally occurring nucleotide substitution mutations in the T beta R-11 gene in human head and neck cancer cells, which may explain their resistance to TGF beta 1-mediated cell cycle arrest.