Prognostic role of c-met expression in breast cancer patients

Background

Hepatocyte growth factor plays an important role in tumor growth, metastasis and angiogenesis. C-met is HGF''s high affinity receptor.

Aim

The aim of the study was to assess the correlations between c-met expression and clinic-pathological factors in breast cancer tissues. Furthermore, the purpose of the study was to evaluate the prognostic value of the hepatocyte growth factor receptor (HGFR, c-met) expressions in homogenous group of breast cancer patients.

Materials and methods

Tumor samples were collected from 302 patients with breast carcinoma treated with primary surgery. We have assessed the percentage of tumor cells with c-met expression, the intensity of reaction and the ratio of these two factors—immunoreactivity according to the Remmele score.

Results

We have observed no correlations between HGFR immunoreactivities and clinical parameters (tumor size, grade, axillary lymph node status, age). In 5-year observation we have found prognostic value of assessing c-met immunoreactivity in primary tumor.

Conclusion

Our study has revealed prognostic value of c-met. Unlike in other authors’ studies, our patients’ group is very homogenous which might contribute to obtained results.     

Identification and methicillin resistance of coagulase-negative staphylococci isolated from nasal cavity of healthy horses

The aim of this study was an analysis of the staphylococcal flora of the nasal cavity of 42 healthy horses from 4 farms, along with species identification of CoNS isolates and determination of resistance to 18 antimicrobial agents, particularly phenotypic and genotypic methicillin resistance. From the 81 swabs, 87 staphylococci were isolated. All isolates possessed the gap gene but the coa gene was not detected in any of these isolates. Using PCR-RFLP of the gap gene, 82.8% of CoNS were identified: S. equorum (14.9%), S. warneri (14.9%), S. sciuri (12.6%), S. vitulinus (12.6%), S. xylosus (11.5%), S. felis (5.7%), S. haemolyticus (3.4%), S. simulans (3.4%), S. capitis (1.1%), S. chromogenes (1.1%), and S. cohnii subsp. urealyticus (1.1%). To our knowledge, this was the first isolation of S. felis from a horse. The species identity of the remaining Staphylococcus spp. isolates (17.2%) could not be determined from the gap gene PCR-RFLP analysis and 16S rRNA gene sequencing data. Based on 16S-23S intergenic transcribed spacer PCR, 11 different ITS-PCR profiles were identified for the 87 analyzed isolates. Results of API Staph were consistent with molecular identification of 17 (19.5%) isolates. Resistance was detected to only 1 or 2 of the 18 antimicrobial agents tested in the 17.2% CoNS isolates, including 6.9% MRCoNS. The mecA gene was detected in each of the 5 (5.7%) phenotypically cefoxitin-resistant isolates and in 12 (13.8%) isolates susceptible to cefoxitin. In total, from 12 horses (28.6%), 17 (19.5%) MRCoNS were isolated. The highest percentage of MRCoNS was noted among S. sciuri isolates (100%).     

Clonal structure and reduced diversity of the invasive alien plant Erigeron annuus in Lithuania

The alien species Erigeron annuus (L.) Pers. is in an intensive spreading phase in Lithuania. Random amplified polymorphic DNA (RAPDs) and inter-simple sequence repeats (ISSRs) assays were used to study the genetic structure of old and new invasive populations and to determine the most spread genotypes of this species in Lithuania. Pairwise genetic distances between populations established using RAPD and ISSR markers significantly correlated (r=0.91, P<0.05). Our study indicates that there are two genetically different types of E. annuus populations. The first type is represented by a widely spread main clone and related monomorphic populations. The second type is represented by polymorphic populations, some of them present at sites where E. annuus has not been previously observed. Main clone predominates in nine populations and is from the region where this species was first described in natural ecosystems of Lithuania. UPGMA cluster analysis revealed genetic relationships between the main clone and accessions from old cemeteries where E. annuus has been grown as an ornamental plant. We found high genetic differentiation among populations (G _ST=0.58 for RAPDs, G _ST=0.64 for ISSRs). Taken together, our results will contribute to the monitoring of E. annuus spread in Lithuania.     

Hydrogen bonded supramolecular structures of cationic and anionic module assemblies containing square-planar oximate complex anions

The formation of the molecular assemblies consisting of anionic and cationic molecules may lead to their interesting structural properties. In this work, we present three new structures based on the tetradentate oxime and amide open-chain ligand CH₃-C(NOH)-C(O)-NH-(CH₂)₃-NH-C(O)-C(NOH)-CH₃ (PAP). All the structures contain the complex cations, complex anions [M(PAP-3H)]⁻ and solvating water molecules. These are H-bonded complex anions: [Ni(1,3-pn)₂(H₂O)₂][Ni(PAP-3H)]₂ · 4 H₂O (1), [Ni(Im)₄(H₂O)₂][Ni(PAP-3H)]₂ (2) and [Cu(Im)₄(H₂O)₂][Cu(PAP-3H)]₂ · 2H₂O (3) (Im=imidazole; 1-3-pn=1,3-diaminopropane). All compounds were synthesised by co-crystallisation of octahedral amine-containing cationic complex with oxime-containing anionic complexes in methanol solution. They were compared with some earlier reported assemblies based on the same ligand (PAP). The comparison of the structures reveals one distinct difference in the separation between the cis-situated oximate oxygen atoms O(1)?O(4) in the copper complexes. The consequence of this effect is the lengthening of the Cu-N distances. In the nickel complexes containing [Ni(PAP-3H)]⁻ anion this effect is much less pronounced.     

Staphylokinase--a specific plasminogen activator

Staphylokinase is a 135 amino acid protein produced by certain strains of Staphylococcus aureus. It belongs to fibrin-specific plasminogen activator. Staphylokinase converts plasminogen--the inactive proenzyme--to the plasmin, which dissolves the fibrin of a blood clots. This review will focus on the biochemical and thrombolytic properties of staphylokinase and its derivatives, which would make use of treatment in acute myocardial infarction and other cardiovascular diseases.     

Role of polyamines in the cytokinin-dependent physiological processes II. Modulation of polyamine levels during cytokinin-stimulated expansion of cucumber cotyledons

The cucumber cotyledon expansion test was used as a model system to study a possible relationship between cytokinin and polyamines. When kinetin was applied to excised cotyledons incubated in the dark it caused a marked increase in the activity of arginine decarboxylase. As a result of ADC action, putrescine content also rose markedly, whereas the level of spermidine and spermine decreased. However, inhibition of putrescine biosynthesis with D-arginine did not affect cytokinin promotion growth. Applied alone, putrescine had no significant effect on growth. These results indicate that the large increase in putrescine content that derives from cytokinin treatment cotyledons is not essential for cytokinin-induced expansion of cotyledons. Addition of K⁺ and Ca²⁺ ions to the cotyledons incubated with cytokinin caused a marked reduction in the putrescine level and ADC activity. The higher level of putrescine (35 %) and spermine (62 %) bound to chromatin and the large increase (174 %) in spermidine content bound to ribosomes which derive from cytokinintreated cotyledons in relation to literature data can indicate that these polyamines may play an important role in gene expression during cytokinin-stimulated expansion of cucumber cotyledons. The inhibition of cytokinin effect, viz. enlargement of the cotyledons by inhibitors of spermidine biosynthesis, additionally suggessted a possible involvement of polyamines in cytokinin action.     

Derivatives of 1-(2-Deoxy-2-fluoro-β-D-arabinofuranosyl)-5-phenyluracil and 5-Benzyluracil. Synthesis and Biological Properties

Abstract

A number of 1-(2-deoxy-2-fluoro-β-D-arabinofuranosyl)uracil and -cytosine nucleosides substituted at the 5 position with a nitrophenyl or nitrobenzyl group were synthesized from 5-phenyl- and 5-benzyluracil via condensation of the fluorinated sugar, followed by nitration. The corresponding amino analogues were also prepared by reduction of the nitro nucleosides. The uracil nucleosides were converted into the corresponding cytosine nucleosides by way of the triazole intermediates. None of these nucleosides exhibited significant activity against herpes simplex virus type 1 in Vero cells. However, cytosine nucleosides containing the o-nitrophenyl, p-nitrophenyl, p-nitrobenzyl or p-aminobenzyl substituent were found to be toxic (even at 1 μM) to uninfected Vero cells, although they were essentially nontoxic in HL-60 cells. The 5′-monophosphates of the uracil nucleosides were inhibitors of the reaction catalyzed by purified Ehrlich ascites carcinoma thymidylate synthase, the 5-phenyluracil nucleotides causing a strong inhibition, competitive vs dUMP, described by the K_i value of 0.01 μM.     

Rapid production of wheat cell suspension cultures directly from immature embryos

The aim of this study was to produce suspension cultures of winter wheat directly from immature embryos bypassing the callus stage, and to determine their capacity for growth and regeneration in comparison to suspension cultures produced from callus. The study was carried out using Polish winter wheat varieties: ‘Grana’ and ‘Rosa’. Immature embryos were isolated, homogenized and transferred directly to liquid medium supplemented with 2,4-D. Actively dividing cell cultures were obtained within 2 months after the cultures were started. Suspension cultures from callus of immature embryos was also produced. With both cultivars, faster growth was observed in the suspension cultures produced directly from embryos than in the suspensions produced from callus. Metabolic activity was higher in the suspension culture produced directly from embryos than in the suspension derived from callus only in ‘Grana’. The production of 1-amiocyclopropane-1-carboxylic acid (ACC), an ethylene precursor, was lower in the suspension cultures produced directly from embryos than in the suspensions produced from callus. Morphogenic capacity was significantly higher in aggregates derived directly from embryos than in aggregates derived from callus. With ‘Rosa’, about one third of the aggregates derived directly from embryos regenerated shoots. Production of ACC was lower in ‘Rosa’ cell culture that regenerated then in other cell cultures that did not. Photosystem II reactions were more efficient in dark green aggregates than in light green or pale green aggregates which were unable to regenerate. With the method presented, wheat cell suspension cultures with a regeneration potential can be produced in 2 or 3 months less time than with traditional methods.     

Regulation of K+ current in human airway epithelial cells by exogenous and autocrine adenosine

The regulatory actions ofadenosine on ion channel function are mediated by four distinctmembrane receptors. The concentration of adenosine in the vicinity ofthese receptors is controlled, in part, by inwardly directed nucleosidetransport. The purpose of this study was to characterize the effects ofadenosine on ion channels in A549 cells and the role of nucleosidetransporters in this regulation. Ion replacement and pharmacologicalstudies showed that adenosine and an inhibitor of human equilibrative nucleoside transporter (hENT)-1, nitrobenzylthioinosine, activated K⁺ channels, most likely Ca²⁺-dependentintermediate-conductance K⁺ (I_K)channels. A₁ but not A₂ receptor antagonistsblocked the effects of adenosine. RT-PCR studies showed that A549 cellsexpressed mRNA for I_K-1 channels as well asA₁, A_2A, and A_2B but notA₃ receptors. Similarly, mRNA for equilibrative (hENT1 andhENT2) but not concentrative (hCNT1, hCNT2, and hCNT3) nucleosidetransporters was detected, a result confirmed in functional uptakestudies. These studies showed that adenosine controls the function ofK⁺ channels in A549 cells and that hENTs play a crucialrole in this process.

     

Phylogenetic relationships, host affinity, and geographic structure of boreal and arctic endophytes from three major plant lineages

Although associated with all plants, fungal endophytes (microfungi that live within healthy plant tissues) represent an unknown proportion of fungal diversity. While there is a growing appreciation of their ecological importance and human uses, little is known about their host specificity, geographic structure, or phylogenetic relationships. We surveyed endophytic Ascomycota from healthy photosynthetic tissues of three plant species (Huperzia selago, Picea mariana, and Dryas integrifolia, representing lycophytes, conifers, and angiosperms, respectively) in northern and southern boreal forest (Québec, Canada) and arctic tundra (Nunavut, Canada). Endophytes were recovered from all plant species surveyed, and were present in <1-41% of 2 mm2 tissue segments examined per host species. Sequence data from the nuclear ribosomal internal transcribed spacer region (ITS) were obtained for 280 of 558 isolates. Species-accumulation curves based on ITS genotypes remained non-asymptotic, and bootstrap analyses indicated that a large number of genotypes remain to be found. The majority of genotypes were recovered from only a single host species, and only 6% of genotypes were shared between boreal and arctic communities. Two independent Bayesian analyses and a neighbor-joining bootstrapping analysis of combined data from the nuclear large and small ribosomal subunits (LSUrDNA, SSUrDNA; 2.4 kb) showed that boreal and arctic endophytes represent Dothideomycetes, Sordariomycetes, Chaetothyriomycetidae, Leotiomycetes, and Pezizomycetes. Many well-supported phylotypes contained only endophytes despite exhaustive sampling of available sequences of Ascomycota. Together, these data demonstrate greater than expected diversity of endophytes at high-latitude sites and provide a framework for assessing the evolution of these poorly known but ubiquitous symbionts of living plants.