EFFECT OF EDTA ADDITIONS ON NATURAL TRICHODESMIUM SPP. (CYANOPHYTA) POPULATIONS1

Despite nearly two decades of intensive research, many questions regarding the physiology and ecology of the marine, non‐heterocystous cyanobacterium, Trichodesmium, remain unresolved. We note here the effect of EDTA (ethylenediaminetetraacetate) on N₂ fixation by Trichodesmium, and the use of EDTA as a means of extending the viability of natural Trichodesmium spp. populations. We examined nitrogenase activity (NA) as a function of EDTA concentration, time of collection, light level, and iron addition. Samples collected early in the day and treated with EDTA maintain a steady rate of activity for hours longer than controls. Furthermore, samples preincubated through the night with EDTA were active the next morning, compared with controls that were inactive. The discovery that (10–50 μM) low concentrations of EDTA prolong the duration of NA of Trichodesmium during experimental manipulations without affecting the rate of acetylene reduction allows for longer term manipulative experiments to be conducted.     

A 140‐kDa glycopeptide from the sperm ligand of the vitelline coat of the freshwater bivalve Unio elongatulus,only contains O‐linked oligosaccharide chains and mediates sperm‐egg interaction

In previous studies we found that sperm binding activity in the vitelline coat of the freshwater bivalve Unio elongatulus is located on the O‐linked oligosaccharide chains of gp273, one of the two major components of the extracellular coat, and that fucose plays a key role in this interaction. In this paper we report the partial characterization of a large glycopeptide (about 140 kDa) obtained by cyanogen bromide fragmentation of gp273, that maintains sperm binding activity. Lectin blotting revealed that the glycopeptide reacted with lectins from Arachis hypogaea (PNA) and Lotus tetragonolobus (LTA) but not Canavalia ensiformis (ConA). No other PNA‐positive fragments could be detected in the electrophoretic pattern of fragmented gp273 but several ConA‐positive fragments of lower molecular weight were present indicating that all the O‐linked chains are clustered together in this fragment. Two‐dimensional gel electrophoresis of the fragment revealed it to be acidic in nature in contrast with the neutral character of the whole gp273 molecule. Competition binding assay showed that this fragment is a strong inhibitor of the interaction, whereas no effect was detected using the ConA‐positive peptides. This confirms that the sperm receptor activity of gp273 is related to its O‐linked chains. The immunodominance of this fragment is also discussed. Mol. Reprod. Dev. 54:203–207, 1999. © 1999 Wiley‐Liss, Inc.     

CytokineDB: a database collecting biological information

Cytokines are subdivided in 12 sub-families and are described as multi-functional molecules that play an important biological activity in host defense system against pathogens, in homeostasis, tissue repair, cell growth and development. CytokineDB is an annotated database that collects biological information regarding the cytokines family in human and will be periodically updated by including new biological information. This database is freely available online and can be accessed at the URL: http://www.cro-m.eu/CytokineDB/     

The oligodeoxynucleotide sequences corresponding to never-expressed peptide motifs are mainly located in the non-coding strand

Background  

We study the usage of specific peptide platforms in protein composition. Using the pentapeptide as a unit of length, we find that in the universal proteome many pentapeptides are heavily repeated (even thousands of times), whereas some are quite rare, and a small number do not appear at all. To understand the physico-chemical-biological basis underlying peptide usage at the proteomic level, in this study we analyse the energetic costs for the synthesis of rare and never-expressed versus frequent pentapeptides. In addition, we explore residue bulkiness, hydrophobicity, and codon number as factors able to modulate specific peptide frequencies. Then, the possible influence of amino acid composition is investigated in zero- and high-frequency pentapeptide sets by analysing the frequencies of the corresponding inverse-sequence pentapeptides. As a final step, we analyse the pentadecamer oligodeoxynucleotide sequences corresponding to the never-expressed pentapeptides.     

The cerebrovascular dysfunction induced by slow pressor doses of angiotensin II precedes the development of hypertension

Hypertension alters cerebrovascular regulation and increases the brain's susceptibility to stroke and dementia. We investigated the temporal relationships between the arterial pressure (AP) elevation induced by "slow pressor" angiotensin II (ANG II) infusion, which recapitulates key features of human hypertension, and the resulting cerebrovascular dysfunction. Minipumps delivering saline or ANG II for 14 days were implanted subcutaneously in C57BL/6 mice (n = 5/group). Cerebral blood flow was assessed by laser-Doppler flowmetry in anesthetized mice equipped with a cranial window. With ANG II (600 ng · kg(-1) · min(-1)), AP started to rise after 9 days (P < 0.05 vs. saline), remained elevated at 11-17 days, and returned to baseline at 21 days (P > 0.05). ANG II attenuated the cerebral blood flow increase induced by neural activity (whisker stimulation) or endothelium-dependent vasodilators, an effect observed before the AP elevation (7 days), as well as after the hypertension subsided (21 days). Nonpressor doses of ANG II (200 ng · kg(-1) · min(-1)) induced cerebrovascular dysfunction and oxidative stress without elevating AP (P > 0.05 vs. saline), whereas phenylephrine elevated AP without inducing cerebrovascular effects. ANG II (600 ng · kg(-1) · min(-1)) augmented neocortical reactive oxygen species (ROS) with a time course similar to that of the cerebrovascular dysfunction. Neocortical application of the ROS scavenger manganic(I-II)meso-tetrakis(4-benzoic acid)porphyrin or the NADPH oxidase peptide inhibitor gp91ds-tat attenuated ROS and cerebrovascular dysfunction. We conclude that the alterations in neurovascular regulation induced by slow pressor ANG II develop before hypertension and persist beyond AP normalization but are not permanent. The findings unveil a striking susceptibility of cerebrovascular function to the deleterious effects of ANG II and raise the possibility that cerebrovascular dysregulation precedes the elevation in AP also in patients with ANG II-dependent hypertension.     

A novel approach for multi-domain and multi-gene family identification provides insights into evolutionary dynamics of disease resistance genes in core eudicot plants

Background

Recent advances in DNA sequencing techniques resulted in more than forty sequenced plant genomes representing a diverse set of taxa of agricultural, energy, medicinal and ecological importance. However, gene family curation is often only inferred from DNA sequence homology and lacks insights into evolutionary processes contributing to gene family dynamics. In a comparative genomics framework, we integrated multiple lines of evidence provided by gene synteny, sequence homology and protein-based Hidden Markov Modelling to extract homologous super-clusters composed of multi-domain resistance (R)-proteins of the NB-LRR type (for NUCLEOTIDE BINDING/LEUCINE-RICH REPEATS), that are involved in plant innate immunity.

Results

To assess the diversity of R-proteins within and between species, we screened twelve eudicot plant genomes including six major crops and found a total of 2,363 NB-LRR genes. Our curated R-proteins set shows a 50% average for tandem duplicates and a 22% fraction of gene copies retained from ancient polyploidy events (ohnologs). We provide evidence for strong positive selection and show significant differences in molecular evolution rates (Ka/Ks-ratio) among tandem- (mean = 1.59), ohnolog (mean = 1.36) and singleton (mean = 1.22) R-gene duplicates. To foster the process of gene-edited plant breeding, we report species-specific presence/absence of all 140 NB-LRR genes present in the model plant Arabidopsis and describe four distinct clusters of NB-LRR “gatekeeper” loci sharing syntenic orthologs across all analyzed genomes.

Conclusion

By curating a near-complete set of multi-domain R-protein clusters in an eudicot-wide scale, our analysis offers significant insight into evolutionary dynamics underlying diversification of the plant innate immune system. Furthermore, our methods provide a blueprint for future efforts to identify and more rapidly clone functional NB-LRR genes from any plant species.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2164-15-966) contains supplementary material, which is available to authorized users.     

Safety and Tolerability of Conserved Region Vaccines Vectored by Plasmid DNA,Simian Adenovirus and Modified Vaccinia Virus Ankara Administered to Human Immunodeficiency Virus Type 1-Uninfected Adults in a Randomized,Single-Blind Phase I Trial

Trial Design

HIV-1 vaccine development has advanced slowly due to viral antigenic diversity, poor immunogenicity and recently, safety concerns associated with human adenovirus serotype-5 vectors. To tackle HIV-1 variation, we designed a unique T-cell immunogen HIVconsv from functionally conserved regions of the HIV-1 proteome, which were presented to the immune system using a heterologous prime-boost combination of plasmid DNA, a non-replicating simian (chimpanzee) adenovirus ChAdV-63 and a non-replicating poxvirus, modified vaccinia virus Ankara. A block-randomized, single-blind, placebo-controlled phase I trial HIV-CORE 002 administered for the first time candidate HIV-1- vaccines or placebo to 32 healthy HIV-1/2-uninfected adults in Oxford, UK and elicited high frequencies of HIV-1-specific T cells capable of inhibiting HIV-1 replication in vitro. Here, detail safety and tolerability of these vaccines are reported.

Methods

Local and systemic reactogenicity data were collected using structured interviews and study-specific diary cards. Data on all other adverse events were collected using open questions. Serum neutralizing antibody titres to ChAdV-63 were determined before and after vaccination.

Results

Two volunteers withdrew for vaccine-unrelated reasons. No vaccine-related serious adverse events or reactions occurred during 190 person-months of follow-up. Local and systemic events after vaccination occurred in 27/32 individuals and most were mild (severity grade 1) and predominantly transient (<48 hours). Myalgia and flu-like symptoms were more strongly associated with MVA than ChAdV63 or DNA vectors and more common in vaccine recipients than in placebo. There were no intercurrent HIV-1 infections during follow-up. 2/24 volunteers had low ChAdV-63-neutralizing titres at baseline and 7 increased their titres to over 200 with a median (range) of 633 (231-1533) post-vaccination, which is of no safety concern.

Conclusions

These data demonstrate safety and good tolerability of the pSG2.HIVconsv DNA, ChAdV63.HIVconsv and MVA.HIVconsv vaccines and together with their high immunogenicity support their further development towards efficacy studies.

Trial Registration

ClinicalTrials.gov {"type":"clinical-trial","attrs":{"text":"NCT01151319","term_id":"NCT01151319"}}NCT01151319     

Assessment of the Selenoprotein M (SELM) Over-Expression on Human Hepatocellular Carcinoma Tissues by Immunohistochemistry

Selenium is an essential trace mineral of fundamental importance to human healthy and exerts its biological function through selenoproteins. In particular, Selenoprotein M (SELM) is located in the endoplasmic reticulum and contains the common redox motif of cysteine-X-X-selenocysteine type. It attracts great attention due to its high expression in brain and its potential roles as antioxidant, neuroprotective, and cytosolic calcium regulator. Recently, our group found SELM over-expression in human hepatocellular carcinoma (HCC) cell lines. In this report some paraffin-embedded tissues from liver biopsy of patients with hepatitis C virus (HCV)-related cirrhosis and HCC were immunohistochemically stained and SELM expression scoring was evaluated. Our results evidence for the first time an increase of SELM expression in HCC liver tissues, and its gradual expression raise associated with an increased malignancy grade. Therefore, we propose to use i) SELM as putative marker for HCC as well as ii) simple immunohistochemistry technique to distinguish between the different grades of malignancy.Key words: Hepatocellular carcinoma, SELM, immunohistochemistry