Chemical composition and antimicrobial activity of the essential oil of Teucrium ramosissimum (Lamiaceae)

The phytochemical composition of the essential oil of Teucrium ramosissimum (aerial parts), harvested in a mountainous region of Tunisia, was analyzed. A total of 68 compounds, accounting for 99.44% of the essential oil, were identified by GC and GC/MS. The major compounds were beta-eudesmol (61; 44.52%), caryophyllene oxide (56; 9.35%), alpha-thujene (1; 5.51%), sabinene (4; 4.71%), and T-cadinol (59; 3.9%). The essential oil, which is being used in Tunisian folk medicine against infectious diseases, was tested for its antimicrobial properties against five different bacteria, and found to have weak to moderate activity, with minimal-inhibitory-concentration (MIC) and minimal-bactericidal-concentration (MBC) values in the range 0.24-0.36 and 1.3-2.9 mg/ml, resp.     

Supramolecular structure of self-assembling alamethicin analog studied by ESR and PELDOR

Three analogs of alamethicin F50/5, labelled with the TOAC (='2,2,6,6-tetramethylpiperidin-1-oxyl-4-amino-4-carboxylic acid') spin label at positions 1 (Alm1), 8 (Alm8), and 16 (Alm16), resp., were studied by Electron-Spin-Resonance (ESR) and Pulsed Electron-Electron Double-Resonance (PELDOR) techniques in solvents of different polarity to investigate the self-assembly of amphipathic helical peptides in membrane-mimicking environments. In polar solvents, alamethicin forms homogeneous solutions. In the weakly polar chloroform/toluene 1 : 1 mixture, however, this peptide forms aggregates that are detectable at 293 K by ESR in liquid solution, as well as by PELDOR in frozen, glassy solution at 77 K. In liquid solution, free alamethicin molecules and their aggregates show rotational-mobility correlation times tau(r) of 0.87 and 5.9 ns, resp. Based on these values and analysis of dipole-dipole interactions of the TOAC labels in the aggregates, as determined by PELDOR, the average number N of alamethicin molecules in the aggregates is estimated to be less than nine. A distance-distribution function between spin labels in the supramolecular aggregate was obtained. This function exhibits two maxima: a broad one at a distance of 3.0 nm, and a wide one at a distance of ca. 7 nm. A molecular-dynamics (MD)-based model of the aggregate, consisting of two parallel tetramers, each composed of four molecules arranged in a 'head-to-tail' fashion, is proposed, accounting for the observed distances and their distribution.     

Subcellular proteomics of cell differentiation: quantitative analysis of the plasma membrane proteome of Caco-2 cells

Human colorectal carcinoma (Caco-2) cells undergo in culture spontaneous enterocytic differentiation, characterized by polarization and appearance of the functional apical brush border membrane. To provide insights into the biology of differentiation, we have performed a comparative proteomic analysis of the plasma membranes from proliferating cells (PCs) and the apical membranes from differentiated cells (DCs). Proteins were resolved by SDS-PAGE, in-gel digested and analyzed by RP-LC and MS/MS. Alternatively, proteins were digested in solution, and tryptic peptides were labeled with isotopic tags and analyzed by 2-D LC followed by MS/MS. Among the 1125 proteins identified in both proteomes, 76 were found to be significantly increased in the membranes of DCs and 61 were increased in PCs. Majority of the proteins increased in the apical membranes were metabolic enzymes, proteins involved in the maintenance of cellular structure, transmembrane transporters, and proteins regulating vesicular transport. In contrast, majority of the proteins increased in the membranes of PCs were involved in gene expression, protein synthesis, and folding. Both groups contained many novel proteins with yet to be identified functions, which could provide potential new markers of the intestinal cells or of colorectal cancer.     

The Light Quanta Modulated Physiological Response of Brassica Juncea Seedlings Subjected to Ni(II) Stress

This work is a study of the inter‐relationship between parameters that principally affect the metal up‐take in the plant. The relationships between the concentration of metal in the growth medium, C_s, the concentration of metal absorbed by the plant, C_p, and the total biomass achieved, M, all of which are factors relevant to the efficiency of phytoremediation of the plant, have been investigated via the macro‐physiological response of Brassica juncea seedlings to Ni(II) stress. The factorial growth experiments treated the Ni(II) concentration in the agar gel and the diurnal light quanta (DLQ) as independently variable parameters. Observations included the evidence of light enhancement of Ni toxicity at the root as well as at the whole plant level, the shoot mass index as a possible indicator of shoot metal sequestration in B. juncea, the logarithmic variation of C_p with C_s and the power‐law dependence of M on C_p. The sum total of these observations indicates that for the metal accumulator B. juncea with regard to its capacity to accumulate Ni, the overall metabolic nature of the plant is important – neither rapid biomass increase nor a high metal concentration capability favor the removal of high metal mass from the medium, but rather the plant with the moderate photosynthetically driven biomass growth and moderate metal concentrations demonstrated the ability to remove the maximum mass of metal from the medium. The implications of these observations in the context of the perceived need in phytoremediation engineering to maximize C_p and M simultaneously in the same plant, are discussed.     

Dacron Patch Aortoplasty of Thoracic Aortic Pseudoaneurysm due to Penetrating Atherosclerotic Ulcer

We report the case of a patient with severe diffuse peripheral vascular disease, coronary artery disease, congestive heart failure, and gastrointestinal bleeding with a pseudoaneurysm of descending thoracic aorta who underwent successful Dacron patch aortoplasty. She was not a candidate for stent-graft repair because of poor access. Using a partial occluding clamp, the pseudoaneurysm was excised and the aorta repaired with a 3.5-cm Dacron patch. She was discharged home in 7 days and has successfully undergone stenting of the left subclavian artery and right and left carotid endarterectomy.     

Endometrial carcinoma biomarker discovery and verification using differentially tagged clinical samples with multidimensional liquid chromatography and tandem mass spectrometry

The utility of differentially expressed proteins discovered and identified in an earlier study (DeSouza, L., Diehl, G., Rodrigues, M. J., Guo, J., Romaschin, A. D., Colgan, T. J., and Siu, K. W. M. (2005) Search for cancer markers from endometrial tissues using differentially labeled tags iTRAQ and cleavable ICAT with multidimensional liquid chromatography and tandem mass spectrometry. J. Proteome Res. 4, 377-386) to discriminate malignant and benign endometrial tissue samples was verified in a 40-sample iTRAQ (isobaric tags for relative and absolute quantitation) labeling study involving normal proliferative and secretory samples and Types I and II endometrial cancer samples. None of these proteins had the sensitivity and specificity to be used individually to discriminate between normal and cancer samples. However, a panel of pyruvate kinase, chaperonin 10, and alpha1-antitrypsin achieved the best results with a sensitivity, specificity, predictive value, and positive predictive value of 0.95 each in a logistic regression analysis. In addition, three new potential markers were discovered, whereas two other proteins showed promising trends but were not detected in sufficient numbers of samples to permit statistical validation. Differential expressions of some of these candidate biomarkers were independently verified using immunohistochemistry.     

Air pollution distribution patterns in the San Bernardino Mountains of southern California: a 40-year perspective

Since the mid-1950s, native pines in the San Bernardino Mountains (SBM) in southern California have shown symptoms of decline. Initial studies in 1963 showed that ozone (O3) generated in the upwind Los Angeles Basin was responsible for the injury and decline of sensitive trees. Ambient O3 decreased significantly by the mid-1990s, resulting in decreased O3 injury and improved tree growth. Increased growth of trees may also be attributed to elevated atmospheric nitrogen (N) deposition. Since most of the N deposition to mixed conifer forest stands in the SBM results from dry deposition of nitric acid vapor (HNO3) and ammonia (NH3), characterization of spatial and temporal distribution of these two pollutants has become essential. Although maximum daytime O3 concentrations over last 40 years have significantly decreased (approximately 3-fold), seasonal means have been reduced much less (approximately 1.5-fold), with 2-week long means occasionally exceeding 100 ppb in the western part of the range. In the same area, significantly elevated concentrations of HNO3 and NH3, up to 17.5 and 18.5 microg/m3 as 2-week averages, respectively, have been determined. Elevated levels of O3 and increased N deposition together with long-term drought predispose the SBM forests to massive bark beetle attacks making them susceptible to catastrophic fires.     

Developmental evolution of sexual ornamentation: model and a test of feather growth and pigmentation

A tremendous diversity of avian color displays has stimulatednumerous studies of natural and sexual selection. Yet, the developmentalmechanisms that produce such diversification, and thus the proximatetargets of selection pressures, are rarely addressed and poorlyunderstood. In particular, because feathers are colored duringgrowth, the dynamics of feather growth play a deterministicrole in the variation in ornamentation. No study to date, however,has addressed the contribution of feather growth to the expressionof carotenoid-based ornamentation. Here, we examine the developmentalbasis of variation in ornamental feather shapes in male housefinches (Carpodacus mexicanus)—a species in which carotenoiddisplays are under strong natural and sexual selection. First,we use geometric morphometrics to partition the observed shapevariation in fully grown feathers among populations, ages, degreesof elaboration, ornamental body parts, and individuals. Second,we use a biologically informed mathematical model of feathergrowth to predict variation in shape of ornamental feathersdue to simulated growth rate, angle of helical growth of featherbarbs, initial number of barb ridges, rate of addition of newbarbs, barb diameter, and ramus-expansion angle. We find closeconcordance between among-individual variation in feather shapeand hue of entire ornament, and show that this concordance canbe attributed to a shared mechanism—growth rate of featherbarbs. Predicted differences in feather shape due to rate ofaddition of barbs and helical angle of feather growth explainedobserved variation in ornamental area both among individualsand between populations, whereas differences in helical angleof growth and the number of barbs in the feather follicle explaineddifferences in feather shape between ornamental parts and amongmales of different ages. The findings of a close associationof feather growth dynamics and overall ornamentation identifythe proximate targets of selection for elaboration of sexualdisplays. Moreover, the close association of feather growthand pigmentation not only can reinforce condition-dependencein color displays, but can also enable phenotypic and geneticaccommodation of novel pigments into plumage displays providinga mechanism for the observed concordance of within-populationdevelopmental processes and between-population diversificationof color displays.     

Evolution of ontogeny: linking epigenetic remodeling and genetic adaptation in skeletal structures

Evolutionary diversifications are commonly attributed to thecontinued modifications of a conserved genetic toolkit of developmentalpathways, such that complexity and convergence in organismalforms are assumed to be due to similarity in genetic mechanismsor environmental conditions. This approach, however, confoundsthe causes of organismal development with the causes of organismaldifferences and, as such, has only limited utility for addressingthe cause of evolutionary change. Molecular mechanisms thatare closely involved in both developmental response to environmentalsignals and major evolutionary innovations and diversificationsare uniquely suited to bridge this gap by connecting explicitlythe causes of within-generation variation with the causes ofdivergence of taxa. Developmental pathways of bone formationand a common role for bone morphogenetic proteins (BMPs) inboth epigenetic bone remodeling and the evolution of major adaptivediversifications provide such opportunity. We show that variationin timing of ossification can result in similar phenotypic patternsthrough epigenetically induced changes in gene expression andpropose that both genetic accommodation of environmentally induceddevelopmental pathways and flexibility in development acrossenvironments evolve through heterochronic shifts in bone maturationrelative to exposure to unpredictable environments. We suggestthat such heterochronic shifts in ossification can not onlybuffer development under fluctuating environments while maintainingepigenetic sensitivity critical for normal skeletal formation,but also enable epigenetically induced gene expression to generatespecialized morphological adaptations. We review studies ofenvironmental sensitivity of BMP pathways and their regulationof formation, remodeling, and repair of cartilage and bone toexamine the hypothesis that BMP-mediated skeletal adaptationsare facilitated by evolved reactivity of BMPs to external signals.Surprisingly, no empirical study to date has identified themolecular mechanism behind developmental plasticity in skeletaltraits. We outline a conceptual framework for future studiesthat focus on mediation of phenotypic plasticity in skeletaldevelopment by the patterns of BMP expression.     

Stimulated PI3K-AKT signaling mediated through ligand or radiation-induced EGFR depends indirectly, but not directly, on constitutive K-Ras activity

Previous results showed an inducible radiation sensitivity selectively observable for K-RAS-mutated cell lines as a function of epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor blockade of phosphatidylinositol 3-kinase (PI3K)-AKT signaling. Therefore, the role of K-Ras activity for a direct (i.e., through activation of PI3K by K-Ras) or an indirect stimulation of PI3K-AKT signaling (through K-Ras activity-dependent EGFR ligand production) was investigated by means of small interfering RNA and inhibitor approaches as well as ELISA measurements of EGFR ligand production. K-RASmt tumor cells presented a constitutively activated extracellular signal-regulated kinase-1/2 signaling, resulting in enhanced production and secretion of the EGFR ligand amphiregulin (AREG). Medium supernatants conditioned by K-RASmt tumor cells equally efficiently stimulated EGFR signaling into the PI3K-AKT and mitogen-activated protein kinase pathways. Knocking down K-Ras expression by specific small interfering RNA markedly affected autocrine production of AREG, but not PI3K-AKT signaling, after treatment of K-RAS-mutated or wild-type cells with EGFR ligands or exposure to ionizing radiation. These results indicate that PI3K-mediated activation of AKT in K-RASmt human tumor cells as a function of EGFR ligand or radiation stimulus is independent of a direct function of K-Ras enzyme activity but depends on a K-Ras-mediated enhanced production of EGFR ligands (i.e., most likely AREG) through up-regulated extracellular signal-regulated kinase-1/2 signaling. The data provide new differential insight into the importance of K-RAS mutation in the context of PI3K-AKT-mediated radioresistance of EGFR-overexpressing or EGFR-mutated tumors.