Some meteorological conditions associated with forest fires in Galicia (Spain)

The present paper offers data on the effect of certain meteorological parameters on the outbreak of forest fires in Galicia (Spain). In a day-to-day analysis, the values of the stability of the air column and the saturation deficit at the lower levels are related to the number of fires occurring in the following 24 h.     

Potential long-acting contraceptive agents: esters of testosterone with alkoxy- and halogeno-substituted carboxylic acids

The chemical synthesis and physical data of several new esters of testosterone (17 beta-hydroxyandrost-4-en-3-one), which contain either a halogeno or an alkoxy substituent in the acid chain, are reported.     

Species specificity and intraspecific variation in the chemical profiles of Heliconius butterflies across a large geographic range

In many animals, mate choice is important for the maintenance of reproductive isolation between species. Traits important for mate choice and behavioral isolation are predicted to be under strong stabilizing selection within species; however, such traits can also exhibit variation at the population level driven by neutral and adaptive evolutionary processes. Here, we describe patterns of divergence among androconial and genital chemical profiles at inter‐ and intraspecific levels in mimetic Heliconius butterflies. Most variation in chemical bouquets was found between species, but there were also quantitative differences at the population level. We found a strong correlation between interspecific chemical and genetic divergence, but this correlation varied in intraspecific comparisons. We identified “indicator” compounds characteristic of particular species that included compounds already known to elicit a behavioral response, suggesting an approach for identification of candidate compounds for future behavioral studies in novel systems. Overall, the strong signal of species identity suggests a role for these compounds in species recognition, but with additional potentially neutral variation at the population level.     

Isolation and characterization of polymorphic microsatellite markers in lesser kestrel (Falco naumanni) and cross-amplification in common kestrel (Falco tinnunculus)

Lesser kestrel, Falco naumanni, is a colonial and migratory species breeding in part of the Mediterranean Basin and part of central Asia and north-east of China and Mongolia. This species is catalogued in IUCN red list category as vulnerable. Twenty microsatellite loci were selected from libraries enriched in AC or AG tandem repeats and specific PCR were devised from their flanking sequences. Most microsatellites (14) were found polymorphic among 30 individuals of F. naumanni representing 20 reproduction areas of the species in the region of Extremadura, Spain. Polymorphisms were detected by size variation of the amplified loci, which allele number and observed heterozygosity ranged from 3 to 20 and from 0.300 to 0.933, respectively. Cross-species amplification showed that 13 of selected loci were also found polymorphic in common kestrel species (Falco tinnunculus). Novel polymorphic microsatellites will serve to conservation studies in lesser kestrel.     

Entamoeba histolytica uses ferritin as an iron source and internalises this protein by means of clathrin-coated vesicles

Entamoeba histolytica is a parasitic protozoan that produces dysentery and often reaches the liver, leading to abscess formation. Ferritin is an iron-storage protein that is mainly found in liver and spleen in mammals. The liver contains a plentiful source of iron for amoebae multiplying in that organ, making it a prime target for infection since iron is essential for the growth of this parasite. The aim of this study was to determine whether trophozoites are able to take up ferritin and internalise this protein for their growth in axenic culture. Interaction between the amoebae and ferritin was studied by flow cytometry, confocal laser-scanning microscopy and transmission electron microscopy. Amoebae were viable in iron supplied by ferritin. Trophozoites quickly internalised ferritin via clathrin-coated vesicles, a process that was initiated within the first 2 min of incubation. In 30 min, ferritin was found colocalizing with the LAMP-2 protein at vesicles in the cytosol. The uptake of ferritin was time- temperature- and concentration-dependent, specific and saturated at 46 nM of ferritin. Haemoglobin and holo-transferrin did not compete with ferritin for binding to amoebae. Amoebae cleaved ferritin leading to the production of several different sized fragments. Cysteine proteases of 100, 75 and 50 kDa from amoeba extracts were observed in gels copolymerised with ferritin. For a pathogen such as E. histolytica, the capacity to utilise ferritin as an iron source may well explain its high pathogenic potential in the liver.     

Anti-atherogenic and anti-angiogenic activities of polyphenols from propolis

Propolis is a polyphenol-rich resinous substance extensively used to improve health and prevent diseases. The effects of polyphenols from different sources of propolis on atherosclerotic lesions and inflammatory and angiogenic factors were investigated in LDL receptor gene (LDLr?/?) knockout mice. The animals received a cholesterol-enriched diet to induce the initial atherosclerotic lesions (IALs) or advanced atherosclerotic lesions (AALs). The IAL or AAL animals were divided into three groups, each receiving polyphenols from either the green, red or brown propolis (250 mg/kg per day) by gavage. After 4 weeks of polyphenol treatment, the animals were sacrificed and their blood was collected for lipid profile analysis. The atheromatous lesions at the aortic root were also analyzed for gene expression of inflammatory and angiogenic factors by quantitative real-time polymerase chain reaction and immunohistochemistry. All three polyphenol extracts improved the lipid profile and decreased the atherosclerotic lesion area in IAL animals. However, only polyphenols from the red propolis induced favorable changes in the lipid profiles and reduced the lesion areas in AAL mice. In IAL groups, VCAM, MCP-1, FGF, PDGF, VEGF, PECAM and MMP-9 gene expression was down-regulated, while the metalloproteinase inhibitor TIMP-1 gene was up-regulated by all polyphenol extracts. In contrast, for advanced lesions, only the polyphenols from red propolis induced the down-regulation of CD36 and the up-regulation of HO-1 and TIMP-1 when compared to polyphenols from the other two types of propolis. In conclusion, polyphenols from propolis, particularly red propolis, are able to reduce atherosclerotic lesions through mechanisms including the modulation of inflammatory and angiogenic factors.     

Expression of nonstructural rotavirus protein NSP4 mimics Ca2+ homeostasis changes induced by rotavirus infection in cultured cells

Rotavirus infection modifies Ca²⁺ homeostasis, provoking an increase in Ca²⁺ permeation, the cytoplasmic Ca²⁺ concentration ([Ca²⁺]_cyto), and total Ca²⁺ pools and a decrease in Ca²⁺ response to agonists. A glycosylated viral protein(s), NSP4 and/or VP7, may be responsible for these effects. HT29 or Cos-7 cells were infected by the SA11 clone 28 strain, in which VP7 is not glycosylated, or transiently transfected with plasmids coding for NSP4-enhanced green fluorescent protein (EGFP) or NSP4. The permeability of the plasma membrane to Ca²⁺ and the amount of Ca²⁺ sequestered in the endoplasmic reticulum released by carbachol or ATP were measured in fura-2-loaded cells at the single-cell level under a fluorescence microscope or in cell suspensions in a fluorimeter. Total cell Ca²⁺ pools were evaluated as ⁴⁵Ca²⁺ uptake. Infection with SA11 clone 28 induced an increase in Ca²⁺ permeability and ⁴⁵Ca²⁺ uptake similar to that found with the normally glycosylated SA11 strain. These effects were inhibited by tunicamycin, indicating that inhibition of glycosylation of a viral protein other than VP7 affects the changes of Ca²⁺ homeostasis induced by infection. Expression of NSP4-EGFP or NSP4 in transfected cells induced the same changes observed with rotavirus infection, whereas the expression of EGFP or EGFP-VP4 showed the behavior of uninfected and untransfected cells. Increased ⁴⁵Ca²⁺ uptake was also observed in cells expressing NSP4-EGFP or NSP4, as evidenced in rotavirus infection. These results indicate that glycosylated NSP4 is primarily responsible for altering the Ca²⁺ homeostasis of infected cells through an initial increase of cell membrane permeability to Ca²⁺.     

Autonomous replication sequences in an extrachromosomal element of a pathogenic Entamoeba histolytica.

Entamoeba histolytica possesses a 24.5 kilobase plasmid-like molecule which encodes for the organism's ribosomal RNAs. Sequence analysis of this extrachromosomal element revealed the presence of AT rich sequences which show homology to the origin of replication of other lower eucaryotes. An 802 bp fragment containing these sequences was cloned into a yeast shuttle vector lacking the origin of replication and the construct tested for its ability to replicate autonomously in yeast. Mitotic stability tests as well as evidence for plasmid maintenance indicate that the transformed cells contained self-replicating episomes and not stably integrated molecules. The nucleotide sequence of this ARS-containing fragment is presented.