Broad taxonomic characterization of Verticillium wilt resistance genes reveals an ancient origin of the tomato Ve1 immune receptor

Plant‐pathogenic microbes secrete effector molecules to establish themselves on their hosts, whereas plants use immune receptors to try and intercept such effectors in order to prevent pathogen colonization. The tomato cell surface‐localized receptor Ve1 confers race‐specific resistance against race 1 strains of the soil‐borne vascular wilt fungus Verticillium dahliae which secrete the Ave1 effector. Here, we describe the cloning and characterization of Ve1 homologues from tobacco (Nicotiana glutinosa), potato (Solanum tuberosum), wild eggplant (Solanum torvum) and hop (Humulus lupulus), and demonstrate that particular Ve1 homologues govern resistance against V. dahliae race 1 strains through the recognition of the Ave1 effector. Phylogenetic analysis shows that Ve1 homologues are widely distributed in land plants. Thus, our study suggests an ancient origin of the Ve1 immune receptor in the plant kingdom.     

Seroprevalence of Toxocara antibodies among patients suspected of ocular toxocariasis in Slovenia

Ocular toxocariasis named also ocular larva migrans is caused by larvae of the roundworm Toxocara spp. The purpose of this study was to find out the seroprevalence of Toxocara antibodies in patients suspected of ocular toxocariasis. Between January 2001 and December 2003, sera from 239 ocular patients, aged 3 to 80 years, were examined by ELISA and confirmed by Western blot test. Out of the 239 patients, 172 (72%) were seronegative and 67 (28%) were Toxocara seropositive; 95% CI (22-34%). The median age of Toxocara seropositive patients was 37.6 years. There was no significant difference in the number of Toxocara positive sera between the younger age group (< or = 14 years) and the older age group (> 14 years), p > 0.05. A high rate of Toxocara seropositivity in ocular patients should alert the ophthalmologists in Slovenia to include toxocariasis in the differential diagnosis of eye diseases more frequently.     

Synthesis and Immunostimulating Properties of Novel Adamant‐1‐yl Tripeptides

The aim of this work was to prepare L ‐ and D ‐(adamant‐1‐yl)‐Gly‐L ‐Ala‐D ‐isoGln peptides in order to study their adjuvant (immunostimulating) activities. Adjuvant activity of adamant‐1‐yl tripeptides was tested in the mouse model using ovalbumin as an antigen and in comparison to the peptidoglycan monomer (PGM; β‐D ‐GlcNAc‐(1→4)‐D ‐MurNAc‐L ‐Ala‐D ‐isoGln‐mesoDAP(εNH₂)‐D ‐Ala‐D ‐Ala) and structurally related adamant‐2‐yl tripeptides.     

Surface modified liposomes by mannosylated conjugates anchored via the adamantyl moiety in the lipid bilayer

The aim of the present study was to encapsulate mannosylated 1-aminoadamantane and mannosylated adamantyltripeptides, namely [(2R)-N-(adamant-1-yl)-3-(α,β-d-mannopyranosyloxy)-2-methylpropanamide and (2R)-N-[3-(α-d-mannopyranosyloxy)-2-methylpropanoyl]-d,l-(adamant-2-yl)glycyl-l-alanyl-d-isoglutamine] in liposomes. The characterization of liposomes, size and surface morphology was performed using dynamic light scattering (DLS) and atomic force microscopy (AFM). The results have revealed that the encapsulation of examined compounds changes the size and surface of liposomes. After the concanavalin A (ConA) was added to the liposome preparation, increase in liposome size and their aggregation has been observed. The enlargement of liposomes was ascribed to the specific binding of the ConA to the mannose present on the surface of the prepared liposomes. Thus, it has been shown that the adamantyl moiety from mannosylated 1-aminoadamantane and mannosylated adamantyltripeptides can be used as an anchor in the lipid bilayer for carbohydrate moiety exposed on the liposome surface.     

Streptomyces sp. JS520 produces exceptionally high quantities of undecylprodigiosin with antibacterial, antioxidative, and UV-protective properties

A Gram-positive, red-pigment-producing bacterial strain, designated JS520 was isolated from the pristine sediment from the cave on mountain Miroc in Serbia. Strain was confirmed to belong to Streptomyces genus based on phenotypic and genetic analysis. Streptomyces sp. JS520 has the ability to produce exceptionally high amounts of deep red pigment into both solid and liquid media. Liquid chromatography and mass spectroscopy of the purified pigments revealed the major component to be undecylprodigiosin (93?%) with minor component being oxidatively cyclized derivative. The pigment production was affected by medium composition, temperature, pH, and the aeration rate. By medium optimization, yields of undecylprodigiosin of 138?mg?l^?1 were achieved, what is the highest level of undecylprodigiosin production reported for the members of Gram-positive Streptomyces genus. Purified pigment had antimicrobial properties against bacterial Bacillus and Micrococcus species (50?μg?ml^?1) and against Candida albicans species (100–200?μg?ml^?1 range). The ability to affect auto-oxidation of the linoleic acid was demonstrated for the purified undecylprodigiosin, suggesting antioxidative properties of this pigment. Multiple ecophysiological roles of the pigment were revealed by comparing cultures grown under pigment-producing and pigment-nonproducing conditions. Cells grown under undecylprodigiosin-producing conditions could tolerate presence of hydrogen peroxide exhibiting three times smaller zones of inhibition at 100?mM H₂O₂. Undecylprodigiosin-producing cells were also less susceptible to tetracycline, kanamycin, chloramphenicol, and 8-hydroxyquinoline. While the growth of the cells not producing pigment was completely inhibited by 15?min of exposure to ultraviolet light (254?nm), cells producing undecylprodigiosin and cells supplied with purified pigment in vitro showed survival rates at 22 and 8?%, respectively.     

Measles Virus Infection Induces Terminal Differentiation of Human Thymic Epithelial Cells

Measles virus infection induces a profound immunosuppression that may lead to serious secondary infections and mortality. In this report, we show that the human cortical thymic epithelial cell line is highly susceptible to measles virus infection in vitro, resulting in infectious viral particle production and syncytium formation. Measles virus inhibits thymic epithelial cell growth and induces an arrest in the G₀/G₁ phases of the cell cycle. Moreover, we show that measles virus induces a progressive thymic epithelial cell differentiation process: attached measles virus-infected epithelial cells correspond to an intermediate state of differentiation while floating cells, recovered from cell culture supernatants, are fully differentiated. Measles virus-induced thymic epithelial cell differentiation is characterized by morphological and phenotypic changes. Measles virus-infected attached cells present fusiform and stellate shapes followed by a loss of cell-cell contacts and a shift from low- to high-molecular-weight keratin expression. Measles virus infection induces thymic epithelial cell apoptosis in terminally differentiated cells, revealed by the condensation and degradation of DNA in measles virus-infected floating thymic epithelial cells. Because thymic epithelial cells are required for the generation of immunocompetent T lymphocytes, our results suggest that measles virus-induced terminal differentiation of thymic epithelial cells may contribute to immunosuppression, particularly in children, in whom the thymic microenvironment is of critical importance for the development and maturation of a functional immune system.     

Comparison of different presbyopia treatments: refractive lens exchange with multifocal intraocular lens implantation versus LASIK monovision

There are several methods for presbyopia treatment. Refractive lens exchange (RLE) followed by multifocal intraocular lens (MFIOL) implantation enables high rate of spectacle independence but have some visual disturbances. Laser in Situ Keratomileusis (LASIK) monovision gives patient ability to have good distant vision with dominant eye and good near vision with nondominant eye. In this prospective randomized study we wanted to compare clinical outcomes in patients who underwent either of the mentioned procedures. The first group included 50 patients (N = 100 eyes) who underwent RLE with MFIOL implantation and the second group included 50 patients (N = 100 eyes) who underwent LASIK monovision as presbyopia treatment. Uncorrected distant, near and intermediate visual acuity, patient's subjective satisfaction and visual disturbances were measured. Follow up was 6 months. Patients in RLE group had better near uncorrected visual acuity (UCVA) and patients in LASIK monovision group had better distant and intermediate vision. Patients in RLE group reported visual disturbances (halo, glare). Patients satisfaction and spectacle independence was high in both groups. Refractive lens exchange with multifocal intraocular lens implantation and LASIK monovision are effective methods for presbyopia treatment. LASIK monovision with -0.50D - 1.25D of residual dioptry at nondominant eye in patients under 50 years enables good vision at all distances without affecting stereovision. Patient selection and preoperative counseling are key to success.     

Contributions to molecular systematics of water scavenger beetles (Hydrophilidae,Coleoptera)

Phylogenetic relationships within Hydrophilidae were examined by analyses of separate and combined nuclear and mitochondrial markers (28S rRNA, 18S rRNA, 16S rRNA, 12S rRNA, COI and COII genes). The preferred (Bayesian) tree topology suggests a sister group relationship between Spercheidae and Hydrophilidae, supporting the ‘hydrophilid lineage’; Epimetopidae are placed on the base of the ‘helophorid branch’, the monophyly of Sphaeridiinae is highly supported, nested deeply within Hydrophilidae closest to Enochrus, making Hydrophilinae and Acidocerini paraphyletic; Hydrobius appears as sister taxon to (Hydrochara + Hydrophilus) without a closer relationship to Acidocerini; the hydrophiloid–histeroid sister group relationship is confirmed. The topology of several taxa remains contradictory, and requires further investigations with a larger taxon sampling and additional molecular markers.     

Phenotypic plasticity and character differentiation in a subdivided population ofIris pumila (Iridaceae)

Variation patterns in phenotypic plasticity and broad sense heritability of 26 characters were examined within and among closely adjacent habitats of the bearded iris,Iris pumila. It was found thatI. pumila has considerable differentiation for phenotypic plasticity and genetic variation over short distances. An analysis of relationships between character differentiation and phenotypic plasticity suggests that they could have evolved independently. Possible mechanisms for maintaining local differentiation of the observed plastic and genetic variation are also discussed.     

Somatostatin increases mitogen-induced IL-2 secretion and proliferation of human jurkat T cells via sst3 receptor isotype

The neuropeptide somatostatin (SRIF) modulates normal and leukemia T cell proliferation. However, neither molecular isotypes of receptors nor mechanisms involved in these somatostatin actions have been elucidated as yet. Here we show by using RT-PCR approach that mitogen-activated leukemia T cells (Jurkat) express mRNA for a single somatostatin receptor, sst3. This mRNA is apparently translated into protein since specific somatostatin binding sites (K_I1 = 78 ± 3 pM) were detected in semipurified plasma membrane preparations by using ¹²⁵I-Tyr¹-SRIF14 as a radioligand. Moreover, somatostatin inhibits adenylyl cyclase activity with similar efficiency (IC₅₀ = 23 ± 4 pM) thus strongly suggesting a functional coupling of sst3 receptor to this transduction pathway. The involvement of sst3 receptor in immuno-modulatory actions of somatostatin was assessed by analysis of neuropeptide effects on IL-2 secretion and on proliferation of mitogen-activated Jurkat cells. Our data show that in the concentrations comprised between 10 pM and 10 nM, somatostatin potentiates IL-2 secretion. This effect is correlated with somatostatin-dependent increase of Jurkat cell proliferation since the EC₅₀ concentrations for both actions were almost identical (EC₅₀ = 22 ± 9 pM and EC₅₀ = 12 ± 1 pM for IL-2 secretion and proliferation, respectively). Altogether, these data strongly suggest that in mitogen-activated Jurkat cells, somatostatin increases cell proliferation through the increase of IL-2 secretion via a functional sst3 receptor negatively coupled to the adenylyl cyclase pathway. J. Cell. Biochem. 68:62–73, 1998. © 1998 Wiley-Liss, Inc.