Diterpenes from Salvia mellifera

Two new aromatic diterpenes have been obtained from the aerial part of Salvia mellifera and their structures identified, on the basis of spectral data and chemical correlations, as 11,12,20-trihydroxy-abieta-8,11,13-triene and 11,12,16-trihydroxy- abieta-8,11,13-trien-20-al. The known diterpenes, carnosic acid, carnosol, rosmanol, isorosmanol, galdosol, rosmadial, 9 (10 → 20)-abeo-abieta-8,11,13-triene-10β,11,12-triol (demethylsalvicanol)and salvicanol were also isolated from the same source. The absolute configuration of salvicanol was established by X-ray diffraction analysis of its 11-p-bromobenzoate derivative.     

Summit evergreen shrubs living at a semi-arid treeline: photoprotection systems activation in an open vs an understory site

High-mountain-ecosystems in the Mediterranean-type climate are exceptional because of their outstanding biodiversity but also because of their characteristic drought stress in summer. Still, plant functioning in these habitats has been largely understudied. Here, morphological, photochemical, and biochemical traits were seasonally assessed in six shrubs characterized by contrasting morphological traits, in the Teide mountain in the Canary Islands. Two adjacent populations, the first located in an open site and the second in the understorey of Pinus canariensis treeline forest, were evaluated. We aimed at disentangling (1) the role of morphological and biochemical photoprotective strategies and of their seasonal plasticity to cope with changing environmental conditions in this semiarid ecosystem, (2) how the interspecific differences in biochemical photoprotection are related to leaf morphology and phenology and (3) how living in the understory of the treeline may affect those responses. Our results indicate that both morphological and biochemical traits (particularly leaf habit, morphology and carotenoids from the β-branch) play an intricate role in photoprotection, and that a high interspecific variability exists. According to the down-regulation of photochemical activity and the upregulation of photoprotective molecules, species could be grouped into three types: (1) those more responsive to summer stress (e.g. Descurainia bourgeauana); (2) those more responsive to winter stress (e.g. Pterocephalus lasiospermus, Scrophularia glabrata and Adenocarpus viscosus); and (3) those showing rather constant behavior across seasons (e.g. Spartocytisus supranubius and Erysimum scoparium). In all the species, plants in the open site showed a marked seasonal physiological response in most of the studied parameters. Pinus canariensis canopy buffers environmental abiotic constrains. On a global change scenario, and provided further functional studies are needed, our results pinpoints heterogeneity in the sensitivity of these species against for instance late-frost or summer-heat/drought events, which could easily shift current species distribution in the coming years.     

Biosynthesis of rat sperm outer dense fibers during spermiogenesis. In vivo incorporation of [3H]leucine into the fibrillar complex

The temporal incorporation profile of [3H]leucine into the outer dense fiber polypeptides was determined after the intratesticular injection of the radioisotope. Groups of four rats were killed on alternate days after injection, and the outer dense fibers were isolated from the caput epididymal sperm. The radioactivity incorporated into the whole sperm and into the isolated fibers showed a sharp peak at 10 days after injection. Therefore, considering the known kinetics of spermatogenesis in the rat, the maximal incorporation of radioactivity into the fibers occurred during the second half of spermiogenesis. The radioactivity incorporated into the six major polypeptides of the fibers separated by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate accounted for 95 percent of the total radioactivity associated with the isolated fibrillar complex. Furthermore, analysis of the time-course incorporation of [3H]leucine into the polypeptides of the fibers indicated that the maximal incorporation into each of the six major components took place within the same period of time. Using two different procedures, the specific activity of each major polypeptide was determined at the time of maximal incorporation. It was found that the specific activity of the most abundant components (molecular weights of 30,400 plus 26,000) was approximately twice that of the other polypeptides.     

Effects of the phenotypic polarization state of human leukocytes on the optical absorbance spectrum

This study evaluated the optical absorbance spectrum of human monocytes, neutrophils and lymphocytes polarized, or not, to the inflammatory or immunoregulatory phenotypes. Peripheral human blood leukocytes were isolated and polarized (10 ng/mL) with LPS or IL-4 + LPS for 2 hours. After polarization, cells were washed and incubated for an additional 24 hours (monocytes and lymphocytes) or 12 hours (neutrophils). Next, cells were collected to evaluate the optical absorbance spectrum. The three types of leukocytes exhibited absorbance in the region from 450 to 900 nm, with greater absorbance at wavelengths lower than 570 nm. Lymphocytes had a second region of greater absorbance between 770 and 900 nm. Inflammatory monocytes and lymphocytes showed increased absorbance of blue, green and yellow wavelengths (monocytes), as well as red and infrared wavelengths (monocytes and lymphocytes). Immunoregulatory polarization altered the absorbance of monocytes and lymphocytes very little. Neutrophils treated with LPS or LPS + IL-4 exhibited lower absorbance at wavelengths higher than 575 nm compared to untreated cells. The present findings showed that leukocytes exhibit greater absorbance in regions of the spectrum that have not been much used in photobiomodulation (PBM), and the polarization of these cells can affect their capacity to absorb light. Taken together, these results suggest new perspectives in the use of PBM in the clinical setting depending on the wavelengths and the stage of the inflammatory process.     

Stability and Local Toxicity Evaluation of a Liposomal Prilocaine Formulation

This study reports a physicochemical stability evaluation of a previously reported liposomal prilocaine (PLC_LUV) formulation () before and after steam sterilization as well as its local toxicity evaluation. Prilocaine (PLC) was encapsulated into extruded unilamellar liposomes (LUVs) composed by egg phosphatidylcholine:cholesterol:alfa-tocopherol (4:3:0.07, mole?%). Laser light-scattering analysis (p?>?0.05) and thiobarbituric acid reaction (p?>?0.05) were used to evaluate the liposomes physical (size) and chemical (oxidation) stability, respectively. The prilocaine chemical stability was followed by ¹H-nuclear magnetic resonance. These tests detected no differences on the physicochemical stability of PLC or PLC_LUV, sterilized or not, up to 30 days after preparation (p?>?0.05). Finally, the paw edema test and histological analysis of rat oral mucosa were used to assess the possible inflammatory effects of PLC_LUV. PLC_LUV did not evoke rat paw edema (p?>?0.05), and no significant differences were found in histological analysis, when compared to the control groups (p?>?0.05). The present work shows that PLC_LUV is stable for a 30-day period and did not induce significant inflammatory effects both in the paw edema test and in histological analysis, giving supporting evidence for its safety and possible clinical use in dentistry.     

Modelling wildlife distributions: Logistic Multiple Regression vs Overlap Analysis

We compare the results, benefits and disadvantages of two techniques for modelling wildlife species distribution: Logistic Regression and Overlap Analysis. While Logistic Regression uses mathematic equations to correlate variables with presence/absence of the species. Overlap Analysis simply combine variables with the presence points, eliminating the non-explanatory variables and recombining the others. Both techniques were performed in a Geographic Information System and we attempted to minimise the spatial autocorrelation of data. The species used was the Schreiber's green lizard Lacerta schreiberi and the study area was Portugal, using 10 X 10 km UTM squares. Both techniques identified the same group of variables as the most important for explaining the distribution of the species. Both techniques gave high average correct classification rates for the squares with presence of the species (79% for Logistic Regression and 92% for Overlap Analysis). Correct absence classification was higher with Logistic Regression (73%) than with Overlap Analysis (32%), Overlap Analysis tends to maximise the potential area of occurrence of the species, which induces a reduced correct classification of absences, since many absences will fall in the potential area. This is because a single presence in a given class of a variable makes all the area of that class to be considered as potential. The technique does not consider that the species may occasionally occupy an unfavourable region. Although, in Logistic Regression, modelling procedures are more complex and time-consuming, the results are more statistically robust. Moreover. Logistic Regression has the capability of associating probability of occurrence to the potential area. Overlap Analysis is very simple in building procedures and swift in obtaining reliable potential areas. It is a valid technique especially in exploratory analysis of species distributions or in the initial stages of research when data may be scarce.