Precursor-product relationship between vitellogenin and the yolk proteins as derived from the complete sequence of a Xenopus vitellogenin gene.

In Xenopus laevis four estrogen-responsive genes are expressed simultaneously to produce vitellogenin, the precursor of the yolk proteins. One of these four genes, the gene A2, was sequenced completely, as well as cDNAs representing 75% of the coding region of the gene. From this data the exon-intron structure of the gene was established, revealing 35 exons that give a transcript of 5,619 bp without the poly A-tail. This A2 transcript encodes a vitellogenin of 1,807 amino acids, whose structure is discussed with respect to its function. At the nucleic acid as well as at the protein level no extensive homologies with any sequences other than vitellogenin were observed. Comparison of the amino acid sequence of the vitellogenin A2 molecule with biochemical data obtained from the different yolk proteins allowed us to localize the cleavage products on the vitellogenin precursor as follows: NH2 - lipovitellin I - phosvitin (or phosvette II - phosvette I) - lipovitellin II - COOH.

Equine herpesvirus-2 E10 gene product, but not its cellular homologue, activates NF-kappaB transcription factor and c-Jun N-terminal kinase.

We have previously reported on the death effector domain containing E8 gene product from equine herpesvirus-2, designated FLICE inhibitory protein (v-FLIP), and on its cellular homologue, c-FLIP, which inhibit the activation of caspase-8 by death receptors. Here we report on the structure and function of the E10 gene product of equine herpesvirus-2, designated v-CARMEN, and on its cellular homologue, c-CARMEN, which contain a caspase-recruiting domain (CARD) motif. c-CARMEN is highly homologous to the viral protein in its N-terminal CARD motif but differs in its C-terminal extension. v-CARMEN and c-CARMEN interact directly in a CARD-dependent manner yet reveal different binding specificities toward members of the tumor necrosis factor receptor-associated factor (TRAF) family. v-CARMEN binds to TRAF6 and weakly to TRAF3 and, upon overexpression, potently induces the c-Jun N-terminal kinase (JNK), p38, and nuclear factor (NF)-kappaB transcriptional pathways. c-CARMEN or truncated versions thereof do not appear to induce JNK and NF-kappaB activation by themselves, nor do they affect the JNK and NF-kappaB activating potential of v-CARMEN. Thus, in contrast to the cellular homologue, v-CARMEN may have additional properties in its unique C terminus that allow for an autonomous activator effect on NF-kappaB and JNK. Through activation of NF-kappaB, v-CARMEN may regulate the expression of the cellular and viral genes important for viral replication.

Concise reviews: in vitro-produced pancreas organogenesis models in three dimensions: self-organization from few stem cells or progenitors.

Three-dimensional models of organ biogenesis have recently flourished. They promote a balance between stem/progenitor cell expansion and differentiation without the constraints of flat tissue culture vessels, allowing for autonomous self-organization of cells. Such models allow the formation of miniature organs in a dish and are emerging for the pancreas, starting from embryonic progenitors and adult cells. This review focuses on the currently available systems and how these allow new types of questions to be addressed. We discuss the expected advancements including their potential to study human pancreas development and function as well as to develop diabetes models and therapeutic cells.

HER2 shedding and serum HER2 extracellular domain: Biology and clinical utility in breast cancer.

The transmembrane protein HER2 is over-expressed in approximately 15% of invasive breast cancers as a result of HER2 gene amplification. HER2 proteolytic cleavage (HER2 shedding) generates soluble truncated HER2 molecules that include only the extracellular domain and the concentration of which can be measured in the serum fraction of blood. HER2 shedding also generates a constitutively active truncated intracellular receptor of 95kDa (p95(HER2)). Another soluble truncated HER2 protein (Herstatin), which can also be found in serum, is the product of an alternatively spliced HER2 transcript. Recent preclinical findings may provide crucial insights into the biological and clinical relevance of increased sHER2 concentrations for the outcome of HER2-positive breast cancer and sensitivity to trastuzumab and lapatinib treatment. We present here the most recent findings about the role and biology of sHER2 based on data obtained using a standardized test, which has been cleared by FDA in 2000, for measuring sHER2. This test includes quality control assessments and has been already widely used to evaluate the clinical utility of sHER2 as a biomarker in breast cancer. We will describe in detail data concerning the assessment of sHER2 as a surrogate maker to optimize the evaluation of the HER2 status of a primary tumor and as a prognosis and predictive marker of response to therapies, both in early and metastatic breast cancer.

Ecological assembly rules in plant communities--approaches, patterns and prospects.

Understanding how communities of living organisms assemble has been a central question in ecology since the early days of the discipline. Disentangling the different processes involved in community assembly is not only interesting in itself but also crucial for an understanding of how communities will behave under future environmental scenarios. The traditional concept of assembly rules reflects the notion that species do not co-occur randomly but are restricted in their co-occurrence by interspecific competition. This concept can be redefined in a more general framework where the co-occurrence of species is a product of chance, historical patterns of speciation and migration, dispersal, abiotic environmental factors, and biotic interactions, with none of these processes being mutually exclusive. Here we present a survey and meta-analyses of 59 papers that compare observed patterns in plant communities with null models simulating random patterns of species assembly. According to the type of data under study and the different methods that are applied to detect community assembly, we distinguish four main types of approach in the published literature: species co-occurrence, niche limitation, guild proportionality and limiting similarity. Results from our meta-analyses suggest that non-random co-occurrence of plant species is not a widespread phenomenon. However, whether this finding reflects the individualistic nature of plant communities or is caused by methodological shortcomings associated with the studies considered cannot be discerned from the available metadata. We advocate that more thorough surveys be conducted using a set of standardized methods to test for the existence of assembly rules in data sets spanning larger biological and geographical scales than have been considered until now. We underpin this general advice with guidelines that should be considered in future assembly rules research. This will enable us to draw more accurate and general conclusions about the non-random aspect of assembly in plant communities.

Growth Arrest-Specific Gene 6 product modulates innate immunity in sepsis

Background: Growth Arrest-Specific Gene 6 product (Gas6) is, like anticoagulant protein C, a vitamin K-dependent protein. Our aim was to determine whether Gas6 plays a role in sepsis. Materials and methods: We submitted mice lacking Gas6 (Gas6)/)) or one of its receptors (Axl)/), Tyro3)/) or Mertk)/)) to LPS-induced endotoxemia and peritonitis (cecal ligation and puncture (CLP) and inoculation of E. coli). In addition, we measured Gas6 or its soluble receptors in plasma of eight volunteers that received LPS, 13 healthy subjects, 28 patients with severe sepsis, and 18 patients with non-infectious inflammatory diseases. Results: Gas6 and its soluble receptor sAxl raised in mice models and TNF-a was more elevated in Gas6)/) mice than in wild-type (WT). Protein array showed that before and after LPS injection, titers of 62 cytokines were more elevated in plasma of Gas6)/) than WT mice. Endotoxemia-induced mortality was higher in Gas6)/), Axl)/), Tyro3)/) and Mertk)/) compared to WT mice and mortality subsequent to CLP was amplified in Gas6)/) mice. LPS-stimulated Gas6)/) macrophages produced more cytokines than WT macrophages. This production was dampened by recombinant Gas6. Phosphorylation of Akt in Gas6)/) macrophages was reduced, but p38 phosphorylation and NF-jB translocation were increased. In human, Gas6 raised in plasma after LPS (2 ng/kg). Gas6 and sAxl were higher in patients with severe sepsis than in healthy subjects or control patients, and there was a non-significant trend for higher Gas6 in the survival group. Conclusions: Our data point to Gas6 as a major modulator of innate immunity and provide thereby novel insights into the mechanism of sepsis. Thus Gas6 and its receptors might constitute potential therapeutic targets for the development of new immunomodulating drugs.

Scientific value of systematic reviews: survey of editors of core clinical journals.

BACKGROUND: Synthesizing research evidence using systematic and rigorous methods has become a key feature of evidence-based medicine and knowledge translation. Systematic reviews (SRs) may or may not include a meta-analysis depending on the suitability of available data. They are often being criticised as 'secondary research' and denied the status of original research. Scientific journals play an important role in the publication process. How they appraise a given type of research influences the status of that research in the scientific community. We investigated the attitudes of editors of core clinical journals towards SRs and their value for publication.¦METHODS: We identified the 118 journals labelled as "core clinical journals" by the National Library of Medicine, USA in April 2009. The journals' editors were surveyed by email in 2009 and asked whether they considered SRs as original research projects; whether they published SRs; and for which section of the journal they would consider a SR manuscript.¦RESULTS: The editors of 65 journals (55%) responded. Most respondents considered SRs to be original research (71%) and almost all journals (93%) published SRs. Several editors regarded the use of Cochrane methodology or a meta-analysis as quality criteria; for some respondents these criteria were premises for the consideration of SRs as original research. Journals placed SRs in various sections such as "Review" or "Feature article". Characterization of non-responding journals showed that about two thirds do publish systematic reviews.¦DISCUSSION: Currently, the editors of most core clinical journals consider SRs original research. Our findings are limited by a non-responder rate of 45%. Individual comments suggest that this is a grey area and attitudes differ widely. A debate about the definition of 'original research' in the context of SRs is warranted.

Vaccinia immune globulin: current policies, preparedness, and product safety and efficacy.

In 1980 the World Health Organization declared that smallpox was eradicated from the world, and routine smallpox vaccination was discontinued. Nevertheless, samples of the smallpox virus (variola virus) were retained for research purposes, not least because of fears that terrorist groups or rogue states might also have kept samples in order to develop a bioweapon. Variola virus represents an effective bioweapon because it is associated with high morbidity and mortality and is highly contagious. Since September 11, 2001, countries around the world have begun to develop policies and preparedness programs to deal with a bioterror attack, including stockpiling of smallpox vaccine. Smallpox vaccine itself may be associated with a number of serious adverse events, which can often be managed with vaccinia immune globulin (VIG). VIG may also be needed as prophylaxis in patients for whom pre-exposure smallpox vaccine is contraindicated (such as those with eczema or pregnant women), although it is currently not licensed in these cases. Two intravenous formulations of VIG (VIGIV Cangene and VIGIV Dynport) have been licensed by the FDA for the management of patients with progressive vaccinia, eczema vaccinatum, severe generalized vaccinia, and extensive body surface involvement or periocular implantation following inadvertent inoculation.