Use of intravenous abciximab as adjunctive therapy for carotid angioplasty and stent placement

The benefit of intravenous abciximab as an adjunctive to percutaneous coronary intervention has been demonstrated in large-scale randomized studies. The role of intravenous abciximab is being defined in carotid angioplasty and stent placement as the procedure is gaining popularity for the treatment of high-grade carotid stenosis in patients considered high-risk for carotid endarterectomy. This paper summarizes the pathophysiological basis and the available data for the use of abciximab as an adjunct to carotid artery stenting.     

Plasma lipid hydroperoxides measurement by an automated xylenol orange method

Lipid hydroperoxides (LH) appear to be good candidates as initial biomarkers of oxidative stress. We describe an automated method to quantify it, based on a known principle: oxidation of Fe II to Fe III by lipid hydroperoxides, under acidic conditions, followed by complexation of Fe III by xylenol orange. This method requires only a 10-microl sample volume of heparinized plasma or serum. It has been carried out automatically, with two reagents, in a two-end-point mode with bichromatic detection at 570 and 700 nm. The within-run precision, measured on a low- and a high-level plasma, was 5.0+/-0.3 and 14.0+/-0.6 microM (n=25 for each series). The between-run precision (one run for 18 days), evaluated on two commercial controls, was 5.6+/-0.5 microM (CV=8.9%) and 7.9+/-0.5 microM (CV=6.3%). The recovery of known amounts of tert-butylhydroperoxide (1 and 2 microM) added to human plasma was 98%. The specificity was demonstrated by the excellent correlation of the values of 42 samples measured either directly, with a simple dilution, or after gel permeation chromatography. The reference interval determined on 21 subjects was 4.9+/-1.7 microM. This was in the upper range of previously published values but our recovery and chromatographic experiments strongly suggest that former methods have underestimated the true content of LH in human plasma.     

Hematopoietic protein tyrosine phosphatase suppresses extracellular stimulus-regulated kinase activation

The mitogen-activated protein kinases (MAPKs) are signaling molecules that become enzymatically activated through phosphorylation by diverse stimuli. Hematopoietic cytokines, growth factors, and stimulated lymphocyte antigen receptors may activate specific MAPKs by altering the balance of MAPK-activating protein kinases and the protein phosphatases that target their activation sites. Hematopoietic protein tyrosine phosphatase (HePTP) is a hematopoiesis-specific cytoplasmic protein tyrosine phosphatase whose expression is induced by mitogenic stimuli. To investigate the role of HePTP in hematopoietic development, we constructed mice deficient in this phosphatase using the technique of homologous recombination. Primary lymphocytes from HePTP(-/-) mice show enhanced activation of extracellular stimulus-regulated kinase (ERK) after both phorbol myristate acetate (PMA) and anti-CD3-mediated T-cell receptor (TCR) stimulation, suggesting a true physiological relationship between these two molecules. Activation of MEK, the physiological activator of ERK, by anti-CD3 or PMA is not affected by HePTP deletion. The distribution of hematopoietic lineages in bone marrow and peripheral blood samples and the in vitro proliferative capacity of bone marrow progenitors from HePTP deletion mice do not deviate from those of matched littermate controls. Similarly, lymphocyte activation and development are indistinguishable in HePTP(-/-) mice and controls. We conclude that HePTP is a physiological regulator of ERK on the basis of these studies and hypothesize that its deletion is well compensated for in the developing mouse through reduction of ERK targets or enhancement of physiologically opposed signaling pathways.     

Antibacterial Potential of 2,4-Di-tert-Butylphenol and Calixarene-Based Prodrugs from Thermophilic Bacillus licheniformis Isolated in Algerian Hot Spring

The present investigation reports the isolation, molecular identification and structure elucidation of antibacterial produced by two thermophilic spore-forming bacteria from hot spring (98?°C) of Guelma (Algeria). Morphological, biochemical and physiological characteristics were carried out. The molecular identification by 16S rRNA and 16-23S rRNA ITS-PCR sequencing identified the thermophilic strains as Bacillus licheniformis with 99% of similarity with GenBank accession numbers KX100031 and KX100032. Phenotypic characterization has mentioned several differences between thermophilic isolates and Bacillus licheniformis ATCC 14580. The ability of the thermophilic spore- forming bacteria to produce antibacterial compounds against two multidrug resistance bacteria Pseudomonas aeruginosa (NR_0754828.1) and Staphylococcus aureus (NR_075000.1) in pure and mixed culture was investigated by Radial Diffusion Assay at 55?°C. Structural elucidation of actives compounds was carried out using gas chromatography–mass spectrometry analyses. Antibacterial potency of the thermophilic isolates might be due to the association between two phenolic compounds: 2,4-Di-tert-butyl-phenol as principal active compound and p-tert-butylcalix[4]arene as prodrugs comparing between gas chromatography–mass spectrometry analysis of pure and mixed extract. To the best of our knowledge, this is the first report showing production of p-tert-butylcalix[4]arene and 2,4-Di-tert-butyl-phenol as extremolytes compounds from thermophilic Bacillus licheniformis at 55?°C.     

Antioxidant defence system and physiological responses of Iranian crested wheatgrass (<Emphasis Type="Italic">Agropyron cristatum</Emphasis> L.) to drought and salinity stress

Crested wheatgrass (Agropyron cristatum L.) is a cool-season perennial grass, which has demonstrated its potential for use as turfgrass. However, limited information is available on its drought and salinity tolerance. The main purpose of this study was to investigate the changes in the antioxidant defence system and physiological traits of six Iranian crested wheatgrass genotypes under drought and salinity stresses. The experimental design comprised a split plot with water treatments (control well-watered, salinity stress and water stress) as main plots and genotypes as subplots. This study demonstrated the variations in drought and salinity tolerance among crested wheatgrass genotypes. ‘ACSKI’, ‘ACAMI’ and ‘ACDTI’ generally performed better than other genotypes under drought and salinity conditions, mainly by maintaining higher activities of antioxidant enzymes like superoxide dismutase, peroxidase, catalase, ascorbate peroxidase and non-enzyme antioxidants like glutathione, higher proline and total non-structural carbohydrates content. The increased, decreased, and unchanged activities of antioxidant enzymes in the crested wheatgrass genotypes indicates a different forms of metabolism of antioxidant enzymes in response to drought and salinity stress. In general, drought and salinity stress increases the malondialdehyde (MDA) content and hydrogen peroxide (H₂O₂) content; however, ‘ACSKI’, ‘ACAMI’ and ‘ACDTI’ genotypes could tolerate an increase in MDA content and H₂O₂ content; therefore, lower levels of MDA content and H₂O₂ content were observed. The results showed that increasing levels of diamine oxidase and polyamine oxidase have been associated with increasing drought and salinity tolerance. Based on the biochemical and physiological parameters that were evaluated, we concluded that the genotype ‘ACSKI’ was superior in terms of drought and salinity tolerance. This superiority was mainly a result of better enzymatic and non-enzymatic antioxidant defence system and better osmotic adjustment under stress conditions.     

Partially local three-way alignments and the sequence signatures of mitochondrial genome rearrangements

Background

Genomic DNA frequently undergoes rearrangement of the gene order that can be localized by comparing the two DNA sequences. In mitochondrial genomes different mechanisms are likely at work, at least some of which involve the duplication of sequence around the location of the apparent breakpoints. We hypothesize that these different mechanisms of genome rearrangement leave distinctive sequence footprints. In order to study such effects it is important to locate the breakpoint positions with precision.

Results

We define a partially local sequence alignment problem that assumes that following a rearrangement of a sequence F, two fragments L, and R are produced that may exactly fit together to match F, leave a gap of deleted DNA between L and R, or overlap with each other. We show that this alignment problem can be solved by dynamic programming in cubic space and time. We apply the new method to evaluate rearrangements of animal mitogenomes and find that a surprisingly large fraction of these events involved local sequence duplications.

Conclusions

The partially local sequence alignment method is an effective way to investigate the mechanism of genomic rearrangement events. While applied here only to mitogenomes there is no reason why the method could not be used to also consider rearrangements in nuclear genomes.

     

Allometric scaling relationship between frequency of intestinal contraction and body size in rodents and rabbits

This study aimed to establish an allometric scaling relationship between the frequency of intestinal contractions and body mass of different mammalian species. The frequency of intestinal contractions of rabbit, guinea pig, rat and mouse were measured using an isolated organ system. The isolated rings were prepared from proximal segments of jejunums and the frequency of contractions was recorded by an isometric force procedure. The coefficients of the obtained allometric equation were ascertained by computation of least squares after logarithmic transformation of both body mass and frequency. Significant differences (p?<?0.001) were shown in the frequency of contractions between different species. The highest frequency that corresponded to the mice was 57.7 min^?1 and the 95% confidence interval (CI) ranged from 45.4 to 70, while rabbits showed the lowest frequency (12.71 min^?1, CI: 8.6–16.8). Logarithms of frequency were statistically proportional to logarithms of body mass (r?=?0.99; p?<?0.001). The data fitted an equation $ \mathrm{F}=18.51{{\mathrm{B}}^{-0.31 }} $ and the 95% confidence interval of the exponent ranged from ?0.30 to ?0.32. The results of this study suggest that it is probably possible to extrapolate the intestinal contraction frequency of other mammalian species by the means of allometry scaling.     

Reaction of some tomato cultivars to tomato leaf curl virus and evaluation of the endophytic colonisation with Beauveria bassiana on the disease incidence and its vector,Bemisia tabaci

Tomato line LA1478 and Pusa Ruby were resistant to tomato leaf curl virus (TLCV) disease. They registered higher plant height, number of branches, total phenol content and yield per plant than the other cultivars. Variety Peto 86 was tolerant to the disease while the other popular tomato cultivars, i.e. Ace, Early Pack, Money Maker, Prichard and Strain B were highly susceptible to the disease. Plant height and number of branches per plant revealed significantly positive association with fruit yield per plant. The disease index of TLCV exhibited significant negative correlations with plant height, total phenol content and fruit yield per plant – 0–4 and 5–25 adult whiteflies were observed on resistant susceptible cultivars. In the case of epiphytically colonisation by Beauveria bassiana conidia, not all developing hyphae on the leaf surface penetrated the whitefly cuticle. Many of the germ tubes elongated to a short distance before terminating its growth. On the other hand, the rapid staining of tomato tissues injected with B. bassiana conidial suspension indicates that the entomopathogenic fungus was established inside tomato tissues until the end time of the trial. The direct injection with the spore suspension yielded high post-colonisation, where the fungus was recovered from sites distant from the point of inoculation. This indicates that the fungus has the potential to move throughout the plant tissues. Laboratory bioassay of tomato whitefly feeding on tomato tissues containing B. bassiana conidial spores indicates that plant endophytic colonisation with entomopathogenic fungi may reduce insect survival on these plants. LT₅₀ values of the test diet were between three and four days. The mortality of Bemisia tabaci was high in the case of endophytically colonisation compared to epiphytically one (90.0% compared to 10.0% during three days) for whiteflies fed tomato tissues containing 1.5 × 10⁷ B. bassiana spores/ml. Application of B. bassiana as an artificial endophyte inside tomato plants can be an important component in the integrated control of tomato whiteflies. The endophytic colonising can achieve biocontrol effect based on induced disease resistance in plant tissues. According the available references, this is the first report on B. tabaci controlling by plant endophytic treatment.