Teruelia diezii gen. et sp. nov.: an early polysporangiophyte from the Lower Devonian of the Iberian Peninsula

A new basal land plant, Teruelia diezii gen. et sp. nov., is described from the shallow‐water marine deposits of the Lower Devonian (Lochkovian–Pragian) Nogueras Formation of the Iberian Peninsula (north Gondwana palaeocontinent). Teruelia is preserved as a compression fossil and consists of isotomously branched, robust stems terminated in large, fusiform, twisted sporangia. This morphology suggests that Teruelia is very probably equivalent to Aglaophyton, a permineralized early polysporangiophyte known up to now only from the Lower Devonian (early Pragian to ?earliest Emsian) Rhynie Chert in Scotland (Laurussia palaeocontinent), which represents an early terrestrial hot‐spring ecosystem. Accepted phylogenies identify Aglaophyton as sister to vascular plants. Our phylogeny‐based results identify the Aglaophyton/Teruelia biological entity (i.e. Aglaophyton anatomical characters plus Teruelia external morphology) as the most direct vascular plant precursor. It shows that at least one Rhynie Chert type plant had a much wider distribution than previously known and suggests that Aglaophyton was not restricted to hydrothermal environments, unlike other Rhynie Chert plants.     

The effects of probiotics on PPI-triple therapy for Helicobacter pylori eradication

Background: This study was performed to evaluate whether the addition of probiotics to proton pump inhibitor (PPI)‐based triple therapy increases the likelihood of successful Helicobacter pylori eradication. Materials and Methods: Three hundred and forty‐seven H. pylori‐infected patients were randomized into a triple‐plus‐yogurt group (yogurt group, n = 168) or a triple‐only group (control group, n = 179). Triple therapy consisted of PPI b.i.d., clarithromycin 500 mg b.i.d., and amoxicillin 1 g b.i.d. for 7 days. Yogurt group received triple therapy for 1 week and one bottle of Will yogurt per day for at 3 weeks, starting on the first day of triple therapy. Will yogurt (a Korean brand) contains Lactobacillus acidophilus HY2177, Lactobacillus casei HY2743, Bifidobacterium longum HY8001, and Streptococcus thermophilus B‐1. ¹³C‐urea breath test was performed at least 4 weeks after completion of triple therapy. Eradication rates, compliances, and adverse events were compared. Results: By intention‐to treat analysis the H. pylori eradication rates in the yogurt group 79.2% (133 of 168) was similar to that in the control group 72.1% (129 of 179) (p = .124). However, by per‐protocol (PP) analysis, the eradication rate in the yogurt group, 87.5% (133 of 152) was higher than that in the control group, 78.7% (129 of 164) (p = .037). Common adverse events were metallic taste (11.8%) and diarrhea (8.6%). The frequency of adverse effects in the yogurt group 41.1% (69/168) were higher than in the control group, 26.3% (47 of 179) (p = .003). However, most adverse events were mild to moderate in intensity, and the severities of adverse effects were similar in both groups (p = .401). Conclusions: The addition of Will yogurt to triple therapy did not reduce the side‐effects of triple therapy. But it increased the H. pylori eradication rate by PP analysis, encouraging more research in this field.     

Reaction of [Pt(Gly-Gly-N,N',O)I]- with the N-acetylated dipeptide L-methionyl-L-histidine: selective platination of the histidine side chain by intramolecular migration of the platinum(II) complex

The reaction of the monofunctional [Pt(Gly-Gly-N,N′,O)I]⁻ complex, in which Gly-Gly is the dipeptide glycyl-glycine coordinated through two nitrogen and oxygen atoms, with the N-acetylated dipeptide l-methionyl-l-histidine (MeCOMet-His) studied by ¹H NMR spectroscopy. All reactions were carried out in 50 mM phosphate buffer at pD 7.4 and at 25 °C. In the initial stage of the reaction, the platinum(II) complex forms the kinetically favored [Pt(Gly-Gly-N,N′,O)(MeCOMet-His-S)]⁻ complex, with unidentate coordination of the MeCOMet-His dipeptide through the sulfur atom of the methionine residue. In the second stage of the reaction, complete intramolecular migration of the [Pt(Gly-Gly-N,N′,O)] unit from the sulfur to the N3 nitrogen atom of imidazole was observed and a new platinum(II)-peptide complex, [Pt(Gly-Gly-N,N′,O)(MeCOMet-His-N3)]⁻ was formed. In comparison with previous results obtained for the reaction of [Pt(dien)Cl]⁺ with different methionine- and histidine-containing peptides, this migration reaction was sufficiently fast and strongly selective to the N3 atom of the imidazole ring of the histidine side chain. This study is an important step in the development of new platinum(II) complexes for selective covalent modification of peptides and proteins.     

Molecular Variability and Evolution of the Pectate Lyase (<Emphasis Type="Italic">pel</Emphasis>-2) Parasitism Gene in Cyst Nematodes Parasitizing Different <Emphasis Type="Italic">Solanaceous</Emphasis> Plants

While pectate lyases are major parasitism factors in plant-parasitic nematodes, there is little information on the variability of these genes within species and their utility as pathotype or host range molecular markers. We have analysed polymorphisms of pectate lyase 2 (pel-2) gene, which degrades the unesterified polygalacturonate (pectate) of the host cell-wall, in the genus Globodera. Molecular variability of the pel-2 gene and the predicted protein was evaluated in populations of G. rostochiensis, G. pallida, G. “mexicana” and G. tabacum. Seventy eight pel-2 sequences were obtained and aligned. Point mutations were observed at 373 positions, 57% of these affect the coding part of the gene and produce 129 aa replacements. The observed polymorphism does not correlate either to the pathotypes proposed in potato cyst nematodes (PCN) or the subspecies described in tobacco cyst nematodes. The trees reveal a topology different from the admitted species topology as G. rostochiensis and G. pallida sequences are more similar to each other than to G. tabacum. Species-specific sites, potentially applicable for identification, and sites distinguishing PCN from tobacco cyst nematodes, were identified. As both G. rostochiensis and G. pallida display the same host range, but distinct from G. tabacum, which cannot parasitize potato plants, it is tempting to speculate that pel-2 genes polymorphism may be implicated in this adaptation, a view supported by the fact that no active pectate lyase 2 was found in G. “mexicana”, a close relative of G. pallida that is unable to develop on cultivated potato varieties.     

Biology of the relict fungus-farming ant Apterostigma megacephala Lattke,including descriptions of the male,gyne, and larva

Insectes Sociaux - Fungus-farming “attine” ant agriculture consists of five distinct agricultural systems characterized by a remarkable symbiont fidelity in which five phylogenetic...     

Expression and purification of an FGF9 fusion protein in E. coli,and the effects of the FGF9 subfamily on human hepatocellular carcinoma cell proliferation and migration

Fibroblast growth factor (FGF) 9 has oncogenic activity and plays an important role in the development of ovarian, lung, prostate, and gastric cancers. In the present study, with the aim of reducing the cost of utilizing growth factors in cancer research, a simple and efficient method for the preparation of recombinant human (rh)FGF9 in Escherichia coli was established. The rhFGF9 fusion protein (6 × His-TEV-rhFGF9) and the native protein released by tobacco etch virus (TEV) protease were obtained using a Ni-NTA system, with > 95% purity. Both purified forms of rhFGF9, with and without fusion tags, significantly stimulated the proliferation of NIH3T3 cells. The FGF9 subfamily, including FGF9, FGF16, and FGF20, in addition to rhFGF16, rhFGF9, and rhFGF20, were shown to stimulate the proliferation and migration of HuH7 human hepatocellular carcinoma (HCC) cells. Mechanistic studies revealed that the stimulation of HuH7 cell proliferation and migration with rhFGF9 and rhFGF20 were associated with the activation of the extracellular signal-regulated kinase (ERK) and nuclear factor κB (NF-κB) pathways and matrix metalloproteinase-26 (MMP26). Inhibition of the ERK and NF-κB pathways blocked cell migration, and NF-κB was demonstrated to be regulated by ERK. Therefore, the present study demonstrates a simple method for the preparation of biologically active rhFGF9 protein. Furthermore, the results indicate that exogenous rhFGF9- and rhFGF20-activated ERK/NF-κB signal transduction pathways play important roles in the regulation of HCC cell proliferation and migration, and this discovery helps to find the potential for new solutions of the treatment of liver cancer.

     

Influence of different Sinorhizobium meliloti inocula on abundance of genes involved in nitrogen transformations in the rhizosphere of alfalfa (Medicago sativa L.)

Inoculation of leguminous seeds with selected rhizobial strains is practised in agriculture to ameliorate the plant yield by enhanced root nodulation and nitrogen uptake of the plant. However, effective symbiosis between legumes and rhizobia does not only depend on the capacity of nitrogen fixation but also on the entire nitrogen turnover in the rhizosphere. We investigated the influence of seed inoculation with two indigenous Sinorhizobium meliloti strains exhibiting different efficiency concerning plant growth promotion on nitrogen turnover processes in the rhizosphere during the growth of alfalfa. Quantification of six target genes (bacterial amoA, nirK, nirS, nosZ, nifH and archaeal amoA) within the nitrogen cycle was performed in rhizosphere samples before nodule formation, at bud development and at the late flowering stage. The results clearly demonstrated that effectiveness of rhizobial inocula is related to abundance of nifH genes in the late flowering phase of alfalfa. Moreover, other genes involved in nitrogen turnover had been affected by the inocula, e.g. higher numbers of amoA copies were observed during flowering when the more effective strain had been inoculated. However, the respective gene abundances differed overall to a greater extent between the three plant development stages than between the inoculation variants.     

S-Adenosylhomocysteine hydrolase (AdoHcyase) deficiency: enzymatic capabilities of human AdoHcyase are highly effected by changes to codon 89 and its surrounding residues

Recently, S-adenosylhomocysteine hydrolase deficiency was confirmed for the first time in an adult. Two missense mutations in codons 89 (A>V) and 143 (Y>C) in the AdoHcyase gene were identified [N.R.M. Buist, B. Glenn, O. Vugrek, C. Wagner, S. Stabler, R.H. Allen, I. Pogribny, A. Schulze, S.H. Zeisel, I. Bari?, S.H. Mudd, S-Adenosylhomocysteine hydrolase deficiency in a 26-year-old man, J. Inh. Metab. Dis. 29 (2006) 538-545]. Accordingly, we have proven the Y143C mutation to be highly inactivating [R. Beluzi?, M. Cuk, T. Pavkov, K. Fumi?, I. Bari?, S.H. Mudd, I. Jurak, O. Vugrek, A single mutation at tyrosine 143 of human S-adenosylhomocysteine hydrolase renders the enzyme thermosensitive and effects the oxidation state of bound co-factor NAD, Biochem. J. 400 (2006) 245-253]. Now we report that the A89V exchange leads to a 70% loss of enzymatic activity, respectively. Circular dichroism analysis of recombinant p.A89V protein shows a significantly reduced unfolding temperature by 5.5 degrees C compared to wild-type. Gel filtration of mutant protein is almost identical to wild-type indicating assembly of subunits into the tetrameric complex. However, electrophoretic mobility of p.A89V is notably faster as shown by native polyacrylamide gel electrophoresis implicating changes to the overall charge of the mutant complex. 'Bioinformatics' analysis indicates that Val(89) collides with Thr(84) causing sterical incompatibility. Performing site-directed mutagenesis changing Thr(84) to 'smaller' Ser(84) but preserving similar physico-chemical properties restores most of the catalytic capabilities of the mutant p.A89V enzyme. On the other hand, substitution of Thr(84) with Lys(84) or Gln(84), thereby introducing residues with higher volume in proximity to Ala(89) results in inactivation of wild-type protein. In view of our mutational analysis, we consider changes in charge and the sterical incompatibility in mutant p.A89V protein as main reason for enzyme malfunction with AdoHcyase deficiency as consequence.     

A comparison of in vitro anticancerous activity and mechanism of ethanolic extracts from different Ganoderma genus

Five ethanolic extracts from the mycelia of Ganoderma lucidum, G. tsugae, G. oerstedii, G. subamboinense, and G. resinaceum were respectively studied on their anticancerous activities against leukemic HL-60 cell line in vitro. Results showed that all five extracts potently inhibited HL-60 proliferation. The extract from G. lucidum mycelia exerted the highest activity. Annexin V/PI bivariate flow cytometric analysis further revealed that the five extracts significantly induced early apoptosis in HL-60 cells. The results illustrate that not only G. lucidum but also other Ganoderma species can inhibit cancer cells, and their mechanisms are related to induction of apoptosis. __________ Translated from Journal of Shanghai Normal University (Natural Sciences), 2005, 34(2): 77–81 [译自: 上海师范大学学报 (自然科学版), 2005, 34(2): 77–81]