Direct Evidence for Changes in the Resistance of Legume Root Nodules to O2 Diffusion

Indirect evidence suggests that legumes can adjust rapidly theresistance of their root nodules to O₂ diffusion. Here we describeexperiments using O₂ specific micro-electrodes and dark fieldmicroscopy to study directly the operation of this diffusionbarrier. The O₂ concentration sensed by the electrode decreasedsharply in the region of the inner cortex and was less than1.0 mmol m^–3 throughout the infected tissue in nodulesof both pea (Pisum sativum) and french bean (Phaseolus vulgaris).In a number of experiments the ambient O₂ concentration wasincreased to 40% while the electrode tip was just inside theinner cortex. In 13 out of 21 cases the O₂ concentration atthis position either remained low and unchanged or increasedirreversibly to near ambient values. In the remaining casesthe O₂ concentration increased after 1 to 2.5 min and then decreasedto its former value. These results are ascribed to an increasein resistance of the barrier in response to increased O₂ fluxinto the nodule. It was shown microscopically that air spacesboth at the boundary between the infected zone and the innercortex, and within the infected zone started to disappear 3min after nodules were exposed to high ambient O₂ concentrationsand had disappeared completely after 8 min. These spaces werenot changed by exposure of the nodule for 10 min to either N₂or air. Key words: Oxygen, root nodules, air spaces     

Evolution of the 28S ribosomal RNA gene in anurans: regions of variability and their phylogenetic implications

Fifteen restriction sites were mapped to the 28S ribosomal RNA gene of individuals representing 54 species of frogs, two species of salamanders, a caecilian, and a lungfish. Eight of these sites were present in all species examined, and two were found in all but one species. Alignment of these conserved restriction sites revealed, among anuran 28S rRNA genes, five regions of major length variation that correspond to four of 12 previously identified divergent domains of this gene. One of the divergent domains (DD8) consists of two regions of length variation separated by a short segment that is conserved at least throughout tetrapods. Most of the insertions, deletions, and restriction-site variations identified in the 28S gene will require sequence-level analysis for a detailed reconstruction of their history. However, an insertion in DD9 that is coextensive with frogs in the suborder Neobatrachia, a BstEII site that is limited to representatives of two leptodactylid subfamilies, and a deletion in DD10 that is found only in three ranoid genera are probably synapomorphies.      

Primary structure and properties of the Na+/glucose symporter (Sg1S) of Vibrio parahaemolyticus.

Previously, we cloned and sequenced a DNA fragment from Vibrio parahaemolyticus and found four open reading frames (ORFs). Here, we clearly demonstrate that one of the ORFs, ORF1, is the gene (sglS) encoding a Na+/glucose symporter (SglS). We characterize the Na+/glucose symporter produced in Escherichia coli mutant (JM1100) cells which lack original glucose transport activity and galactose transport activity. We also show that phlorizin, a potent inhibitor of the SGLT1 Na+/glucose symporter of animal cells, inhibited glucose transport, but not galactose transport, via the SglS system.     

Virtual Screening to Identify Novel Inhibitors of Pan ERBB Family of Proteins from Natural Products with Known Anti-tumorigenic Properties

International Journal of Peptide Research and Therapeutics - Overexpression of ERBBB family of receptors (ERBB1, ERBB2, ERBB3 and ERBB4) has been found to be hyper-activated in a number of...     

Decomposition of woody debris in Mediterranean ecosystems: the role of wood chemical and anatomical traits

Plant and Soil - Data about woody debris (WD) decomposition are very scarce for the Mediterranean basin. The specific aim of this work is to explore the relationships between WD traits with the...     

A Systematic Review on Phytochemistry,Ethnobotany and Biological Activities of the Genus Bunium L.

The aim of this review article is to present, for the first time, an appraisal of the phytochemical, ethnobotanical and pharmacological data on Bunium species. The literature search was conducted using the Scopus, Google Scholar and PubMed databases. The genus Bunium has been found to produce both essential oil (EO), mainly comprising monoterpenes and sesquiterpenes, and non-volatile components mainly coumarins and flavonoids. There are several pharmacological activities associated with the Bunium species, especially antioxidant, antibacterial and antifungal properties. The chemotaxonomic appraisal of the phytochemical pattern of the genus is in sink with the current classification of the family. Moreover, this review confirms the significant ethnobotanical and pharmacological potential of different Bunium species.     

Timing and abundance of sporangia production and zoospore release influences the recovery of different Phytophthora species by baiting

Analysis of soil samples using High Throughput Sequencing (HTS) frequently detects more Phytophthora species compared with traditional soil baiting methods. This study investigated whether differences between species in the timing and abundance of sporangial production and zoospore release could be a reason for the lower number of species isolated by baiting. Stems of Eucalyptus marginata were inoculated with ten Phytophthora species (P. nicotianae, P. multivora, P. pseudocryptogea, P. cinnamomi, P. thermophila, P. arenaria, P. heveae, P. constricta, P. gondwanensis and P. versiformis), and lesioned sections for each species were baited separately in water. There were significant differences between species in timing of sporangia production and zoospore release. P. nicotianae, P. pseudocryptogea, P. multivora and P. thermophila released zoospores within 8–12 h and could be isolated from lesioned baits within 1–2 days. In contrast, P. constricta did not produce zoospores for over 48 h and was only isolated 5–7 days after baiting. P. heveae and P. versiformis did not produce zoospores and were not recovered from the baits. When species were paired in the same baiting tub, those that produced zoospores in the shortest time were isolated most frequently, while species slow to produce zoospores, or which produced them in lower numbers, were isolated from few baits or not at all. Thus, species differences in the timing of sporangia production and zoospore release may contribute to the ease of isolation of some Phytophthora species when they are present together with other Phytophthora species in an environmental sample.     

Analytical validation of quantitative immunohistochemical assays of tumor infiltrating lymphocyte biomarkers

Tumor infiltrating lymphocytes (TIL), especially T-cells, have both prognostic and therapeutic applications. The presence of CD8+ effector T-cells and the ratio of CD8+ cells to FOXP3+ regulatory T-cells have been used as biomarkers of disease prognosis to predict response to various immunotherapies. Blocking the interaction between inhibitory receptors on T-cells and their ligands with therapeutic antibodies including atezolizumab, nivolumab, pembrolizumab and tremelimumab increases the immune response against cancer cells and has shown significant improvement in clinical benefits and survival in several different tumor types. The improved clinical outcome is presumed to be associated with a higher tumor infiltration; therefore, it is thought that more accurate methods for measuring the amount of TIL could assist prognosis and predict treatment response. We have developed and validated quantitative immunohistochemistry (IHC) assays for CD3, CD8 and FOXP3 for immunophenotyping T-lymphocytes in tumor tissue. Various types of formalin fixed, paraffin embedded (FFPE) tumor tissues were immunolabeled with anti-CD3, anti-CD8 and anti-FOXP3 antibodies using an IHC autostainer. The tumor area of stained tissues, including the invasive margin of the tumor, was scored by a pathologist (visual scoring) and by computer-based quantitative image analysis. Two image analysis scores were obtained for the staining of each biomarker: the percent positive cells in the tumor area and positive cells/mm² tumor area. Comparison of visual vs. image analysis scoring methods using regression analysis showed high correlation and indicated that quantitative image analysis can be used to score the number of positive cells in IHC stained slides. To demonstrate that the IHC assays produce consistent results in normal daily testing, we evaluated the specificity, sensitivity and reproducibility of the IHC assays using both visual and image analysis scoring methods. We found that CD3, CD8 and FOXP3 IHC assays met the fit-for-purpose analytical acceptance validation criteria and that they can be used to support clinical studies.     

NHERF2 Protein Mobility Rate Is Determined by a Unique C-terminal Domain That Is Also Necessary for Its Regulation of NHE3 Protein in OK Cells

Na⁺/H⁺ exchanger regulatory factor (NHERF) proteins are a family of PSD-95/Discs-large/ZO-1 (PDZ)-scaffolding proteins, three of which (NHERFs 1-3) are localized to the brush border in kidney and intestinal epithelial cells. All NHERF proteins are involved in anchoring membrane proteins that contain PDZ recognition motifs to form multiprotein signaling complexes. In contrast to their predicted immobility, NHERF1, NHERF2, and NHERF3 were all shown by fluorescence recovery after photobleaching/confocal microscopy to be surprisingly mobile in the microvilli of the renal proximal tubule OK cell line. Their diffusion coefficients, although different among the three, were all of the same magnitude as that of the transmembrane proteins, suggesting they are all anchored in the microvilli but to different extents. NHERF3 moves faster than NHERF1, and NHERF2 moves the slowest. Several chimeras and mutants of NHERF1 and NHERF2 were made to determine which part of NHERF2 confers the slower mobility rate. Surprisingly, the slower mobility rate of NHERF2 was determined by a unique C-terminal domain, which includes a nonconserved region along with the ezrin, radixin, moesin (ERM) binding domain. Also, this C-terminal domain of NHERF2 determined its greater detergent insolubility and was necessary for the formation of larger multiprotein NHERF2 complexes. In addition, this NHERF2 domain was functionally significant in NHE3 regulation, being necessary for stimulation by lysophosphatidic acid of activity and increased mobility of NHE3, as well as necessary for inhibition of NHE3 activity by calcium ionophore 4-Br-{"type":"entrez-nucleotide","attrs":{"text":"A23187","term_id":"833253","term_text":"A23187"}}A23187. Thus, multiple functions of NHERF2 require involvement of an additional domain in this protein.