Cytotoxicity of some platinum(IV) complexes with ethylenediamine-N,N'-di-3-propionato ligand

The cytotoxicities of two platinum(IV) complexes of formula [PtX2(eddp)].nH2O (eddp=ethylenediamine-N,N'-di-3-propionate, X=chloro [I] or bromo [II], n=1 or 1.24) are reported. The complexes have been obtained by direct reaction of potassium hexahaloplatinate(IV) with H2eddp.2HCl followed by addition of a base (LiOH). The crystal and molecular structure has confirmed that the complex with bromo ligands, similarly to the complex with chloro ligands previously reported, has trans configuration of the halogens. In both the chloro and bromo complexes there appear to be intramolecular N-H...X interactions which account for a narrowing of the corresponding X-Pt-N angles below 90degrees. The trans isomer (configuration index OC-6-13, two nitrogens and two oxygens of eddp bound in the equatorial plane) is the only one obtained in the reaction of hexahaloplatinate(IV) with the eddp ligand while a similar reaction performed with ethylenediamine-N,N'-diacetate (edda) affords exclusively the symmetrical cis-isomer (configuration index OC-6-33, equatorial nitrogen and axial oxygen atoms of edda). The longer chain of the propionato groups (as compared to the acetato ones) is responsible for such a change in preferred configuration. NMR data have revealed a very large diastereotopic splitting of the propionato methylene protons to the nitrogens (0.88 ppm). The trans disposition of the halogen ligands in the compounds with eddp leads to deactivation of platinum(IV) complexes in comparison to those with edda having cis disposition of the leaving chlorides (human ovarian cancer cell line A2780, IC50 [muM] of 92.6 +/- 12 and 30.3 +/- 7.5 for [I] and [II], respectively).     

When do meadow vipers (Vipera ursinii) become sexually dimorphic? – ontogenetic patterns of sexual size dimorphisms

Contrary to an increasing number of papers that document sexual dimorphism in size (and/or shape) in adults, studies dealing with sex differences in newborn and juvenile snakes are surprisingly scarce. Data about ontogenetic shifts in sexual dimorphism are generally lacking and hence, it is unclear whether sex differences are set at birth or arise post‐natally. In this study, we analyzed patterns of sexual dimorphism in body size, head dimensions and tail length (TL) among newborn, subadult and adult meadow vipers (Vipera ursinii) from the Bjelasica Mt. in Montenegro. Patterns of sexual size dimorphisms differed among traits. There was no significant difference in head dimension of males and females, but adult snakes were sexually dimorphic in body size. Sexual differences in TL were evident since birth but changed in degree throughout ontogeny. Neonate meadow vipers presented highly significant inter‐litter variation in the sexual dimorphism of all traits we have measured. Such family effects may have an important influence on extent of inter‐sexual differences in snakes and should be included in analyses of sexual dimorphism.     

Two-dimensional liquid chromatography system for online top-down mass spectrometry

An online metal-free weak cation exchange-hydrophilic interaction LC/RPLC system has been developed for sensitive, high-throughput top-down MS. Here, we report results for analyzing PTMs of core histones, with a focus on histone H4, using this system. With just ～24?μg on-column of core histones (H4, H2B, H2A, and H3) purified from human fibroblasts, 41 H4 isoforms were identified, with the type and location of PTMs unambiguously mapped for 20 of these variants. Compared to corresponding offline studies reported previously, the online weak cation exchange-hydrophilic interaction LC/RPLC platform offers significant improvement in sensitivity, with several orders of magnitude reduction in sample requirements and a reduction in the overall analysis time. To the best of our knowledge, this study represents the first online 2-D LC-MS/MS characterization of core histone mixture at the intact protein level.     

Of mice and men: teratomas and teratocarcinomas

Teratomas and teratocarcinomas are tumors containing tissue derivatives of all three germ-layers. They can be induced by transplantation of animal embryos to ectopic microenvironment. Development of malignant teratocarcinomas depends on embryonic stage, species-specificity and immunological competence of the host. In the man, teratomas and teratocarcinomas usually represent a subtype of germ-cell tumors but sacrococcygeal teratomas arise from the remnants of the pluripotent primitive streak. Undifferentiated embryonal carcinoma (EC) cells are responsible for the malignancy of experimental mouse teratocarcinomas. Mouse EC cells injected to the adult give rise to tumors and upon injection to early embryos to differentiated tissues--thus resembling normal mouse embryonic stem cells (mESC). Epigenetic changes rather than mutations are associated with transformation of mESC to EC cells. Human EC and ES cell-lines (hESC) contain chromosomal abnormalities and can form teratocarcinoma after transplantation. ES cells are among those proposed for cell replacement therapy in the man. Suicide gene introduction should be recommended prior to their use in vivo to ablate them in case of malignant transformation.     

Galectin-1 is part of human trophoblast invasion machinery--a functional study in vitro

Background

Interactions of glycoconjugates with endogenous galectins, have been long proposed to participate in several reproductive processes including implantation. In human placenta gal-1, gal-3, gal-8, and gal-13 proteins are known to be present. Each of them has been proposed to play multiple functions, but so far no clear picture has emerged. We hypothesized that gal-1 participates in trophoblast invasion, and conducted Matrigel invasion assay using isolated cytotrophoblast from first trimester placenta and HTR-8/SVneo cell line to test it.

Methods and Findings

Function blocking anti-gal-1 antibody was employed to assess participation of endogenous gal-1 in cell adhesion, cell invasion of HTR-8/SVneo cells. When gal-1 was blocked in isolated trophoblast cell invasion was reduced to 75% of control (SEM±6.3, P<0.001) and to 66% of control (SEM±1.7, P<0.001) in HTR-8/SVneo cell line. Increased availability of gal-1, as two molecular forms of recombinant human gal-1 (CS-gal-1 and Ox-gal-1), resulted in increased cell invasion by cytotrophoblast to 151% (SEM±16, P<0.01) with 1 ng/ml of CS-gal-1, and to 192% (SEM±51, P<0.05) with 1 µg/ml of Ox-gal-1. Stimulation was also observed in HTR-8/SVneo cells, to 317% (SEM±58, P<0.001) by CS-gal-1, and to 200% (SEM±24, P<0.001) by Ox-gal-1 at 1 µg/ml. Both sets of results confirmed involvement of gal-1 in trophoblast invasion. Galectin profile of isolated cytotrophoblast and HTR-8/SVneo cells was established using RT-PCR and real-time PCR and found to consist of gal-1, gal-3 and gal-8 for both cell types. Only gal-1 was located at the trophoblast cell membrane, as determined by FACS analysis, which is consistent with the results of the functional tests.

Conclusion and Significance

These findings qualify gal-1 as a member of human trophoblast cell invasion machinery.     

Leaf epidermal characteristics of Trifolium L. species from Serbia and Montenegro

A micromorphological analysis of leaf epidermal tissue of 18 Trifolium species was carried out using light and scanning electron microscopy, in order to obtain qualitative and quantitative data on epidermal characteristics and to evaluate their taxonomic significance. The shape of epidermal cells and their cell walls, epidermal wax depositions, presence of papillae, type and number of stomata, type, distribution and number of non-glandular and glandular trichomes were analyzed. The results showed that species that belong to the same section had some common leaf epidermal characteristics. Combinations of those characters proved to be useful in taxonomy at the level of the sections, but not for identification of single species.     

Characterization of purified c-type heme-containing peptides and identification of c-type heme-attachment sites in Shewanella oneidenis cytochromes using mass spectrometry

We describe methods for mass spectrometric identification of heme-containing peptides from c-type cytochromes that contain the CXXCH (X=any amino acid) sequence motif. The heme fragment ion yielded the most abundant MS/MS peak for standard heme-containing peptides with one amino acid difference for both 2+ and 3+ peptide charge states; both sequence and charge affect the extent of heme loss. Application to Shewanella oneidenis demonstrated the utility of this approach for identifying c-type heme-containing peptides from complex proteome samples.     

The Introduced Green Alga Caulerpa Taxifolia Continues to Spread in the Mediterranean

The tropical green alga Caulerpa taxifolia in the Mediterranean has spread steadily since its introduction in 1984. At the end of 2000, approximately 131km² of benthos had been colonized in 103 independent areas along 191km of coastline in six countries (Spain, France, Monaco, Italy, Croatia and Tunisia). Large regions neighboring the invaded areas appear favorable to further colonization, and there is thus no reason to believe that spreading will slow down in the years to come.     

The role of IgG avidity determination in diagnosis of Epstein-Barr virus infection in immunocompetent and immunocompromised patients

There is a high degree of variability in the serologic response to Epstein-Barr virus (EBV) infection, especially in viral capsid antigen (VCA)-IgM antibodies. Therefore, additional tests are needed to confirm primary infection. We evaluated the value of IgG avidity determination in diagnosis of EBV infection in immunocompetent and immunocompromised patients. A total of 236 serum samples from immunocompetent patients with symptoms suggestive of EBV infection were tested for the presence of VCA-IgM/IgG antibodies and IgG avidity. Using IgG avidity, acute primary infection was confirmed in 56.7% of the immunocompetent patients with positive and in 1.8% of patients with negative VCA-IgM. Recent primary infection was documented in 8.9% of the IgM positive and 3.5% of the IgM negative patients. In patients with indeterminate serology (equivocal IgM), 6.7% were classified by avidity index (AI) as acute primary infection, 10.0% as post-acute and 83.3% as past infection cases. Concerning the 32 immunocompromised patients, recent primary infection was documented in 3 of the 14 IgM positive patients. High AI was detected in 11 of these patients, indicating an IgM response due to reactivation. Determination of IgG avidity in combination with classical serologic markers seems to be a reliable method to confirm primary infection both in immunocompetent and immunocompromised patients. It may be especially useful to differentiate cases of primary infection in patients with undetectable VCA-IgM antibodies or indeterminate routine EBV serology.     

An allelopathic investigation of the domination of the introduced invasive Conyza canadensis L.

The introduced, invasive species Conyza canadensis L. covers large areas of the sandy levees next to the River Tamiš (Serbia), forming dense microcomplexes and dominating the other herbaceous species in the ruderal phytocoenosis with its aboveground mass and abundance. In addition to this species, a further 28 plant species were found, but the abundance and cover of these was significantly lower. The allelopathic influence of the species C. canadensis was investigated through analyzing the total phenolics and phenolic acids, as the main allelochemicals, in dead and vegetative parts and the soil beneath them. Seed germination and seedling growth of the target plants (Dactylis glomerata L. and Trifolium repens L.), which grow in this community, served as a measure of the inhibitory capacity of this species. It was established that the content of total phenolics and phenolic acids (p-coumaric, ferulic, p-hydroxybenzoic, vanillic and syringic) varies, following the order: vegetative plant parts > dead plant parts > sandy soil under C. canadensis. Water leachate and soils inhibited seed germination and seedling growth of the test plants to varying degrees, following the order: vegetative parts > dead parts > sandy soil, which is directly related to the content of total phenolics and phenolic acids in them. It was concluded that the pioneer species C. canadensis plays a decisive role in the first phases of vegetation succession and the process of soil formation on the barren sandy levees, owing to the synthesis of secondary phenolic metabolites.