In vitro antimicrobial activity of pannarin alone and in combination with antibiotics against methicillin-resistant Staphylococcus aureus clinical isolates

The in vitro antimicrobial activities of pannarin, a depsidone isolated from lichens, collected in several Southern regions of Chile (including Antarctica), was evaluated alone and in combination with five therapeutically available antibiotics, using checkerboard microdilution assay against methicillin-resistant clinical isolates strains of Staphylococcus aureus. MIC(90), MIC(50), as well as MBC(90) and MBC(50), were evaluated. A moderate synergistic action was observed in combination with gentamicin, whilst antagonism was observed in combination with levofloxacin. All combinations with erythromycin were indifferent, whilst variability was observed for clindamycin and oxacillin combinations. Data from checkerboard assay were analysed and interpreted using the fractional inhibitory concentration index and the response surface approach using the ΔE model. Discrepancies were found between both methods for some combinations. In order to asses cellular lysis after exposure to pannarin, cell membrane permeability assay was performed. The treatment with pannarin produces bactericidal activity without significant calcein release, consistent with lack of lysis or even significant structural damage to the cytoplasmic membrane. Furthermore, pannarin shows low hemolytic activity and moderate cytotoxic effect on peripheral blood mononuclear cells. These findings suggest that the natural compound pannarin might be a good candidate for the individualization of novel templates for the development of new antimicrobial agents or combinations of drugs for chemotherapy.     

Analysis of prey capture and food transport kinematics in two Asian box turtles,Cuora amboinensis and Cuora flavomarginata (Chelonia,Geoemydidae), with emphasis on terrestrial feeding patterns

This study examines the kinematics and morphology of the feeding apparatus of two geoemydid chelonians, the Malayan (Amboina) box turtle (Cuora amboinensis) and the yellow-margined box turtle (Cuora flavomarginata). Both species are able to feed on land as well as in water. Feeding patterns were analysed by high-speed cinematography. The main focus of the present study is on the terrestrial feeding strategies in both Asian box turtles, because feeding on land has probably evolved de novo within the ancestrally aquatic genus Cuora. During terrestrial feeding (analysed for both species), the initial food prehension is always done by the jaws, whereas intraoral food transport and pharyngeal packing actions are tongue-based. The food uptake modes in Cuoras differ considerably from those described for purely terrestrial turtles. Lingual food prehension is typical of all tortoises (Testudinidae), but is absent in C. amboinensis and C. flavomarginata. A previous study on Terrapene carolina shows that this emydid turtle protrudes the tongue during ingestion on land, but that the first contact with the food item occurs by the jaws. Both Asian box turtles investigated here have highly movable, fleshy tongues; nonetheless, the hyolingual complex remains permanently retracted during initial prey capture. In aquatic feeding (analysed for C. amboinensis only), the prey is captured by a fast forward strike of the head (ram feeding). As opposed to ingestion on land, in the underwater grasp the hyoid protracts prior to jaw opening. The head morphology of the investigated species differs. In contrast to the Malayan box turtle, C. flavomarginata exhibits a more complexly structured dorsal lingual epithelium, a considerable palatal vault, weaker jaw adductor muscles and a simplified trochlear complex. The differences in the hyolingual morphology reflect the kinematic patterns of the terrestrial feeding transport.     

Reproducibility and reliability of the Pliensbachian calcareous nannofossil biohorizons from the Basque-Cantabrian Basin (Northern Spain)

Based on calcareous nannofossil assemblages identified in four expanded and well-dated sections from the Basque-Cantabrian Basin, the main objective of this paper is to improve the knowledge of the Pliensbachian calcareous nannofossil events, and to calibrate these events to the ammonite zones established for this area. The semiquantitative analysis of more than 140 smear slides from the Tudanca and Santotis sections, and the re-analysis of more than 200 smear slides from the Camino and San Andrés sections, have been carried out in order to describe the succession of calcareous nannofossil assemblages. Related to their composition changes, we have recognized and calibrated to the ammonite zones two main events: the first occurrences (FOs) of Similiscutum cruciulus and Lotharingius hauffii, and six secondary events: the FOs of Biscutum novum, Biscutum grande, Biscutum finchii, Lotharingius barozii and the FCOs (first common occurrences) of Calcivascularis jansae and L. hauffii. In the Camino and San Andrés sections, we also identify the FOs of Biscutum dubium, Bussonius prinsii and Lotharingius sigillatus. The obtained data allow us to assess the degree of reproducibility of the Pliensbachian calcareous nannofossil events in the studied area. The biohorizon succession recognized in the Basque-Cantabrian Basin are compared to those proposed for NW Europe, Lusitanian Basin, Italy and Southern France.     

Cholesterol levels linked to abnormal plasma thiol concentrations and thiol/disulfide redox status in hyperlipidemic subjects

Treatment of hyperlipidemic patients with the thiol compound N-acetylcysteine (NAC) was previously shown to cause a significant dose-related increase in the high-density lipoprotein (HDL)-cholesterol serum level, suggesting the possibility that its disease-related decrease may result from a diminished thiol concentration and/or thiol/disulfide redox status (REDST) in the plasma. We therefore investigated plasma thiol levels and REDST in normo-/hyperlipidemic subjects with and without coronary heart disease (CHD). The thiol level, REDST, and amino acid concentrations in the plasma and intracellular REDST of peripheral blood mononuclear cells (PBMC) have been determined in 62 normo- and hyperlipidemic subjects. Thirty-three of these subjects underwent coronary angiography, because of clinical symptoms of CHD. All groups of hyperlipidemic patients under test and those normolipidemic individuals with documented coronary stenoses showed a marked decrease in plasma thiol concentrations, plasma and intracellular REDST of PBMCs, and a marked increase in plasma taurine levels. Individual plasma thiol concentrations and plasma REDST were strongly negatively correlated with the serum LDL-cholesterol and positively correlated with the serum HDL-cholesterol level. Together with the earlier report about the effect of NAC on the HDL-cholesterol serum level, our findings suggest strongly that lower HDL-cholesterol serum levels may result from a decrease in plasma thiol level and/or REDST possibly through an excessive cysteine catabolism into taurine.     

Do high progesterone concentrations decrease pregnancy rates in embryo recipients synchronized with PGF2alpha and eCG?

The objective of this study was to evaluate the effects of equine chorionic gonadotropin (eCG) treatment on the number of induced accessory corpora lutea (CL), plasma progesterone concentrations and pregnancy rate in cross-bred heifers after transfer of frozen-thawed (1.5M ethylene glycol) embryos. All recipients received 500 microg PGF2alpha (dl-cloprostenol, i.m.) at random stages of the estrous cycle (Day 0) and were observed for estrus for 7 days. On Day 14, heifers detected in estrus between 2 and 7 days after PGF2alpha treatment were randomly allocated to four groups ( n=83 per group) and given 0 (control), 200, 400, or 600 IU of eCG. Two days later (Day 16), these recipients were given PGF2alpha and observed for estrus. Six to eight days after detection of estrus, plasma samples were collected to determine progesterone concentration and ultrasonography was performed to observe ovarian structures. Heifers with multiple CL or a single CL >15 mm in diameter received an embryo by direct transfer. Embryos of excellent and good quality were thawed and transferred to the recipients by the same veterinarian. Pregnancy was diagnosed by ultrasonography and confirmed by transrectal palpation 21 and 83 days after embryo transfer (ET), respectively. Plasma progesterone concentrations on the day of transfer (Day 7 of the estrous cycle) were 3.9+/-0.7, 4.2+/-0.4,6.0+/-0.4 and 7.8+/-0.6 ng/ml for groups Control, 200, 400, and 600, respectively (Control versus treated groups P=0.009; 200 versus 400 and 600 groups P=0.0001; and 400 versus 600 P=0.012 ). Conception rates 83 days after ET were 41.9, 50.0, 25.0, and 20.9% for groups Control, 200, 400, and 600, respectively (200 versus 400 and 600 groups P=0.0036 ). In conclusion, an increase in progesterone concentration, induced by eCG treatment, did not improve pregnancy rates in ET recipients. Conversely, there was a decline in conception rates in the animals with the highest plasma progesterone concentrations.     

Crataegus special extract WS 1442 improves cardiac function and reduces infarct size in a rat model of prolonged coronary ischemia and reperfusion

In Germany, hydroalcoholic extracts from hawthorn (Crataegus spp.) leaves with flowers are approved drugs for the treatment of mild forms of heart insufficiency. Besides cardiotonic effects these herbal remedies have been shown to possess cardioprotective properties. We now evaluated if treatment of rats with the Crataegus special extract WS 1442 also improves cardiac function and prevents myocardial infarction during prolonged ischemia and reperfusion lasting for 240 and 15 min, respectively. Oral administration of WS 1442 (10 or 100 mg x kg(-1) x day(-1)) for 7 days before ligation of the left coronary artery dose-dependently suppressed the decrease of the pressure rate product. WS 1442 treatment also attenuated the elevation of the ST-segment in the ECG, diminished the incidence of ventricular fibrillations (control: 67%; 10 mg x kg(-1): 64%; 100 mg x kg(-1): 27%) and reduced the mortality rate (control: 47%; 10 mg.kg(-1): 27%; 100 mg x kg(-1): 9%). Furthermore, the area of myocardial infarction within the ischemic zone was significantly smaller in treated rats (10 mg x kg(-1): 64.3 +/- 5.1%; 100 mg x kg(-1): 42.8 +/- 4.1%) when compared with controls (78.4 +/- 2.6%). It is suggested that these pharmacological effects are accounted for by the combined antioxidative, leukocyte elastase inhibiting and endothelial nitric oxide (NO) synthesis enhancing properties of WS 1442.     

Phylogeny of Rozites, Cuphocybe and Rapacea inferred from ITS and LSU rDNA sequences

Phylogenetic relationships of Rozites, Cuphocybe, and Rapacea were assessed using molecular phylogenetic approaches. These three genera are placed in Cortinariaceae and have been regarded as closely related to Cortinarius. Rozites includes more than 20 species, which are characterized by having both a membranaceous partial veil in the form of a persistent annulus and a membranaceous universal veil. Cuphocye (4 species) lacks an annulus or cortina, but has pigmented veil fibrils or scales. The monotypic genus Rapacea accommodates a distinct taxon with pale, nearly smooth and thick-walled basidiospores. We analyzed 56 sequences of the internal transcribed spacer region (ITS1, ITS2, and the intervening 5.8S rRNA gene) for nine species of Rozites, three species of Cuphocybe, 28 species of Cortinarius, Rapacea mariae and Protoglossum luteum. Two species of Hebeloma were used as outgroup. Large subunit (LSU) rDNA sequences from selected taxa were also analyzed. The results clearly demonstrate that Rozites species are nested within the clade/Cortinarius, and that Rozites is polyphyletic, suggesting that membranaceous veils have evolved several times in the genus Cortinarius. Also Rapacea and Cuphocybe are nested within Cortinarius, making the latter genus paraphyletic. Based on phylogenetic studies, Rozites, Cuphocybe and Rapacea are artificial genera and do not reflect natural relationships.