Fire blight resistance of pear genotypes from different European countries

Several old cultivars, and breeding clones of European pear Pyrus communis L. originating from Belgium, England, Sweden, and Switzerland were evaluated for their resistance/susceptibility to fire blight. Studies were carried out during three consecutive years 2007–2009 in the greenhouse of Warsaw University of Life Sciences, Poland. Strain 691 of Erwinia amylovora was used for artificial infection of plants. Genotypes included in this study considerably varied in their resistance to fire blight. The most resistant was the old English cultivar ‘Hessle’. The other two genotypes, i.e., ‘Gr?nna R?dp?ron’ originating from Sweden, and Pyrus communis FG 1606 from Switzerland were included in a group of low susceptible ones. The most susceptible were Cra Py H 18, Cra Py V 22 and Cra Py W 14 from Belgium.     

Effect of γ34.5 deletions on oncolytic herpes simplex virus activity in brain tumors

The ICP34.5 protein of herpes simplex virus (HSV) is involved in many aspects of viral pathogenesis; promoting neurovirulence, inhibiting interferon-induced shutoff of protein synthesis, interacting with PCNA and TBK1, inhibiting dendritic cell (DC) maturation, and binding to Beclin 1 to interfere with autophagy. Because of its key role in neuropathogenicity, the γ34.5 gene is deleted in all oncolytic HSVs (oHSVs) currently in clinical trial for treating malignant gliomas. Unfortunately, deletion of γ34.5 attenuates virus replication in cancer cells, especially human glioblastoma stem cells (GSCs). To develop new oHSVs for use in the brain and that replicate in GSCs, we explored the effect of deleting the γ34.5 Beclin 1 binding domain (BBD). To ensure cancer selectivity and safety, we inactivated the ICP6 gene (UL39, large subunit of ribonucleotide reductase), constructing ICP6 mutants with different γ34.5 genotypes: Δ68HR-6, intact γ34.5; Δ68H-6, γ34.5 BBD deleted; and 1716-6, γ34.5 deleted. Multimutated Δ68H-6 exhibited minimal neuropathogenicity in HSV-1-susceptible mice, as opposed to Δ68H and Δ68HR-6. It replicated well in human glioma cell lines and GSCs, effectively killing cells in vitro and prolonging survival of mice bearing orthotopic brain tumors. In contrast, 1716 and 1716-6 barely replicated in GSCs. Infection of glioma cells with Δ68H-6 and 1716-6 induced autophagy and increased phosphorylation of eIF2α, while inhibition of autophagy, by Beclin 1 short hairpin RNA (shRNA) knockdown or pharmacological inhibition, had no effect on virus replication or phosphorylated eIF2α (p-eIF2α) levels. Thus, Δ68H-6 represents a new oHSV vector that is safe and effective against a variety of brain tumor models.     

Changes of activity and kinetics of certain liver and heart enzymes of hypothyroid and T(3)-treated rats

Thyroid diseases are one of the most common metabolic disorders in the human population. In this work, we present data concerning changes in the activity and kinetic parameters of several enzymes associated with both anabolic (glucose-6-phosphate dehydrogenase-G6PDH, EC 1.1.1.49; 6-phosphogluconate dehydrogenase-6PGDH, EC 1.1.1.44; malic enzyme-ME, EC 1.1.1.40; and isocitrate dehydrogenase-IDH, EC 1.1.1.42) and catabolic (NAD-dependent malate dehydrogenase-NAD-MDH, EC 1.1.1.37; and lactate dehydrogenase-LDH, EC 1.1.1.27) processes under conditions of hypothyroidism and T(3) treatment. Hypothyroidism was induced in rats by the surgical removal of the thyroid gland. T(3)-treated rats were injected by T(3) (0.5 mg T(3)/kg body weight daily during 10 days). We have found that T(3) treatment caused an increase of NAD-MDH activity as well as heart hypertrophy whereas the activity of LDH increased in the direction of pyruvate reduction. Moreover, we observed increased activity of both enzymes in the liver. These results confirm earlier observation concerning the relevance of oxidative metabolism in the heart under T(3) treatment. Hypothyroidism resulted in changes in the LDH activity in the heart whereas NAD-MDH activity did not change. Moreover, our data show that T(3) treatment caused an increase of G6PDH, 6PGDH, and ME activities in the liver. We also observed a decrease of IDH activity in both organs, whereas hypothyroidism caused the opposite effect. This data indicate that either deficiency or excess of thyroid hormones can prove to be particularly dangerous for the physiology of the heart muscle by disturbing bioenergetic and anabolic processes.     

Emergence of a small-world functional network in cultured neurons

The functional networks of cultured neurons exhibit complex network properties similar to those found in vivo. Starting from random seeding, cultures undergo significant reorganization during the initial period in vitro, yet despite providing an ideal platform for observing developmental changes in neuronal connectivity, little is known about how a complex functional network evolves from isolated neurons. In the present study, evolution of functional connectivity was estimated from correlations of spontaneous activity. Network properties were quantified using complex measures from graph theory and used to compare cultures at different stages of development during the first 5 weeks in vitro. Networks obtained from young cultures (14 days in vitro) exhibited a random topology, which evolved to a small-world topology during maturation. The topology change was accompanied by an increased presence of highly connected areas (hubs) and network efficiency increased with age. The small-world topology balances integration of network areas with segregation of specialized processing units. The emergence of such network structure in cultured neurons, despite a lack of external input, points to complex intrinsic biological mechanisms. Moreover, the functional network of cultures at mature ages is efficient and highly suited to complex processing tasks.     

Endothelial cells help in the diagnosis of primary versus metastatic carcinoma of the liver in fine needle aspirates. An immunofluorescence study with vimentin and endothelial cell-specific antibodies

Fine needle aspirates of 5 primary hepatocellular carcinomas and 24 carcinomas metastatic to the liver were studied using vimentin and endothelial cell-specific monoclonal antibodies. Numerous endothelial cells dispersed and in bundles overlying clumps of tumor cells were positively stained by both antibodies in smears of primary hepatocellular carcinomas while such cells were rare or absent in metastatic carcinomas, with the exception of clear cell carcinoma of the kidney. It is concluded that endothelial cells, if present in large numbers in fine needle aspirates of a hepatic carcinoma and arranged in bundles that envelope the clumps of tumor cells, can (1) suggest the presence of a primary hepatocarcinoma and (2) narrow the differential diagnosis with the most common metastatic cancers to renal cell carcinoma.     

The Crystal Structure of the Streptococcal Collagen-like Protein 2 Globular Domain from Invasive M3-type Group A Streptococcus Shows Significant Similarity to Immunomodulatory HIV Protein gp41

The arsenal of virulence factors deployed by streptococci includes streptococcal collagen-like (Scl) proteins. These proteins, which are characterized by a globular domain and a collagen-like domain, play key roles in host adhesion, host immune defense evasion, and biofilm formation. In this work, we demonstrate that the Scl2.3 protein is expressed on the surface of invasive M3-type strain MGAS315 of Streptococcus pyogenes. We report the crystal structure of Scl2.3 globular domain, the first of any Scl. This structure shows a novel fold among collagen trimerization domains of either bacterial or human origin. Despite there being low sequence identity, we observed that Scl2.3 globular domain structurally resembles the gp41 subunit of the envelope glycoprotein from human immunodeficiency virus type 1, an essential subunit for viral fusion to human T cells. We combined crystallographic data with modeling and molecular dynamics techniques to gather information on the entire lollipop-like Scl2.3 structure. Molecular dynamics data evidence a high flexibility of Scl2.3 with remarkable interdomain motions that are likely instrumental to the protein biological function in mediating adhesive or immune-modulatory functions in host-pathogen interactions. Altogether, our results provide molecular tools for the understanding of Scl-mediated streptococcal pathogenesis and important structural insights for the future design of small molecular inhibitors of streptococcal invasion.     

A comprehensive study on the contents and leaching of trace elements from fly-ash originating from polish hard coal by NAA and AAS methods

In order to assess the environmental risks associated with the emission of fly-ash into the atmosphere and its storage on waste heaps, the trace element contents of fly-ashes from burning Polish hard coal were determined by a newly developed INAA method. Leaching of trace elements from the fly-ash by water and H₂SO₄ solution (pH≈2.5) simulating acid rain, respectively, was studied using AAS and spectrophotometric methods. Analogous experiments were done with neutron-irradiated fly-ash, following the composition of the eluate gamma-spectrometrically. The new fine fly-ash (CTA-FFA-1) candidate reference material was prepared, and the certification was undertaken on the basis of an international intercomparison run. Preliminary evaluation of results shows that at least 38 elements will be certified and, in addition, the “information values” for at least 12 elements will be given.