Adenylate cyclase activity of membrane fractions isolated from sea urchin sperm

The adenylate cyclase activity of sperm membrane fragments isolated from Lytechinus pictus sperm according to Cross [20] has been studied. Two distinct fractions preferentially coming from the flagellar plasma membrane are obtained. Surface I¹²⁵-labeling experiments performed by Cross [20] indicate that these membranes are representative of the entire sperm plasma membrane. Both fractions are enriched in their adenylate cyclase activity: the specific activity of the top membranes is eightfold higher than in whole sperm, whereas that of the middle membranes is 15-fold higher. The cyclase seems to be associated with the membranes. Lytechinus pictus egg jelly has no effect or slightly inhibits the adenylate cyclase activity of the isolated sperm plasma membrane fragments. Mg⁺⁺ and Na⁺ stimulated their cyclase activity about sevenfold at 2.5 mM Mn⁺⁺ and 3.2 mM ATP. At this ATP to Mn⁺⁺ ratio, high concentrations of Ca⁺⁺ have a small stimulatory effect.     

An Overview of the Genetic Structure within the Italian Population from Genome-Wide Data

In spite of the common belief of Europe as reasonably homogeneous at genetic level, advances in high-throughput genotyping technology have resolved several gradients which define different geographical areas with good precision. When Northern and Southern European groups were considered separately, there were clear genetic distinctions. Intra-country genetic differences were also evident, especially in Finland and, to a lesser extent, within other European populations. Here, we present the first analysis using the 125,799 genome-wide Single Nucleotide Polymorphisms (SNPs) data of 1,014 Italians with wide geographical coverage. We showed by using Principal Component analysis and model-based individual ancestry analysis, that the current population of Sardinia can be clearly differentiated genetically from mainland Italy and Sicily, and that a certain degree of genetic differentiation is detectable within the current Italian peninsula population. Pair-wise F_ST statistics Northern and Southern Italy amounts approximately to 0.001 between, and around 0.002 between Northern Italy and Utah residents with Northern and Western European ancestry (CEU). The Italian population also revealed a fine genetic substructure underscoring by the genomic inflation (Sardinia vs. Northern Italy = 3.040 and Northern Italy vs. CEU = 1.427), warning against confounding effects of hidden relatedness and population substructure in association studies.     

Effect of Leishmania spp infection on the survival,life expectancy,fecundity and fertility of Lutzomyia longipalpis s.l. and Lutzomyia pseudolongipalpis

We evaluated the effects of Leishmania spp infection on several population parameters of Lutzomyia longipalpis sensu lato andLutzomyia pseudolongipalpis, vectors of visceral leishmaniasis in Venezuela, under experimental conditions during the first post-feeding period. Females of both species were allowed to feed and engorge on a suspension of fresh washed human red blood cells in foetal calf serum. These blood cells were either non-infected or infected with one of the fourLeishmania spp strains and were offered through a chicken skin membrane. The longevity, life expectancy and the fecundity of uninfected flies were similar in both species, but the fertility was significantly lower in uninfected Lu. longipalpis females. In all cases, the infection of Lu. longipalpis and Lu. pseudolongipalpis by the Leishmania strains resulted in significant detrimental effects, which exerted a fitness cost expressed by reduced survival and life expectancy, as well as decreased fertility and fecundity compared with the control groups. Nevertheless, differences in these parameters were observed between these vector species depending on whether they were infected with the autochthonous Venezuelan Leishmania infantum strain (NESA) or the Brazilian reference strain (PP75). The experimental data obtained agree with field data on the natural infection of these vector species and the significance of this scenario is discussed.     

Digoxin Suppresses Pyruvate Kinase M2-Promoted HIF-1α Transactivation in Steatohepatitis

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Flagella from Five Cronobacter Species Induce Pro-Inflammatory Cytokines in Macrophage Derivatives from Human Monocytes

Cronobacter spp. are opportunistic pathogens linked to lie-threatening infections in neonates and contaminated powdered infant formula that has been epidemiologically associated with these cases. Clinical symptoms of Cronobacter include necrotizing enterocolitis, bacteremia, and meningitis. Flagella from C. sakazakii are involved in biofilm formation and its adhesion to epithelial cells. We investigated the role of flagella from C. sakazakii ST1 and ST4, C. malonaticus, C. muytjensii, C. turicensis and C. dublinensis during the activation of cytokines (IL-8, TNF-α, and IL-10) in macrophage derivatives from human monocytes, which has not been extensively studied. The production and identity of flagella from the five Cronobacter species were visualized and recognized with anti-flagella antibodies by immunogold labeling through transmission electron microscopy. Purified flagella were dissociated into monomers in 12% SDS-PAGE Coomassie blue-stained gels showing a band of ∼28 kDa and, in addition, mass spectrometry revealed the presence of several peptides that correspond to flagellin. Flagella (100 ng) induced the release of IL-8 (3314–6025 pg/ml), TNF-α (39–359 pg/ml), and IL-10 (2–96 pg/ml), in macrophage isolates from human monocytes and similar results were obtained when flagella were dissociated into monomers. Inhibition assays using three dilutions of anti-flagella antibodies (1∶10, 1∶100, and 1∶200) suppressed the secretion of IL-8, TNF-α, and IL-10 between 95–100% using 100 ng of protein. A transfection assay using 293-hTLR5 cells showed IL-8 release of 197 pg/ml and suppression in the secretion of IL-8 when anti-hTLR5-IgA antibodies were used at different concentrations. These observations suggest that flagella and flagellin are involved in an inflammatory response dependent on TLR5 recognition, which could contribute to the pathogenesis of the bacteria.     

Genetic susceptibility to malignant pleural mesothelioma and other asbestos-associated diseases

Exposure to asbestos fibers is a major risk factor for malignant pleural mesothelioma (MPM), lung cancer, and other non-neoplastic conditions, such as asbestosis and pleural plaques. However, in the last decade many studies have shown that polymorphism in the genes involved in xenobiotic and oxidative metabolism or in DNA repair processes may play an important role in the etiology and pathogenesis of these diseases. To evaluate the association between diseases linked to asbestos and genetic variability we performed a review of studies on this topic included in the PubMed database. One hundred fifty-nine citations were retrieved; 24 of them met the inclusion criteria and were evaluated in the review. The most commonly studied GSTM1 polymorphism showed for all asbestos-linked diseases an increased risk in association with the null genotype, possibly linked to its role in the conjugation of reactive oxygen species. Studies focused on GSTT1 null and SOD2 Ala16Val polymorphisms gave conflicting results, while promising results came from studies on alpha1-antitrypsin in asbestosis and MPO in lung cancer. Among genetic polymorphisms associated to the risk of MPM, the GSTM1 null genotype and two variant alleles of XRCC1 and XRCC3 showed increased risks in a subset of studies. Results for the NAT2 acetylator status, SOD2 polymorphism and EPHX activity were conflicting. Major limitations in the study design, including the small size of study groups, affected the reliability of these studies. Technical improvements such as the use of high-throughput techniques will help to identify molecular pathways regulated by candidate genes.     

Extracellular proteolytic activity and molecular analysis of Microsporum canis strains isolated from symptomatic and asymptomatic cats

Microsporum canis is the main zoophylic dermatophyte in dogs and cats, and it is also an important zoonotic agent. The literature showed that cats are asymptomatic carriers of M. canis. This is apparently due to host resistance and/or the presence of strains with lower virulence. This study was aimed to evaluate the keratinolytic, elastinolytic and collagenolytic activities of M. canis strains and their relationship with symptomatic and asymptomatic cats. In addition, these strains were analysed by RFLP. The strains isolated from cats with clinical dermatophytosis had higher keratinase and elastase activity than those isolated from asymptomatic animals (p minus than 0.05). There were not differences in RFLP patterns based on Hind III digestion.     

Soil Drench Treatment with ?-Aminobutyric Acid Increases Drought Tolerance of Potato

The non-protein amino acid β-aminobutyric acid (BABA) is known to be a priming agent for a more efficient activation of cellular defence responses and a potent inducer of resistance against biotic and abiotic stresses in plants. Nevertheless, most of the studies on priming have been carried out in Arabidopsis. In potato, the effect of BABA was demonstrated only on biotic stress tolerance. We investigated the effect of BABA on the drought tolerance of potato and found that soil drenched with BABA at a final concentration of 0.3 mM improves the drought tolerance of potato. Water loss from the leaves of the primed plants is attenuated and the yield is increased compared to the unprimed drought-stressed plants. The metabolite composition of the tubers of the BABA-treated plants is less affected by drought than the tuber composition of the non-treated plants. Nitric oxide and ROS (reactive oxygen species) production is increased in the BABA-treated roots but not in the leaves. In the leaves of the BABA-treated plants, the expression of the drought-inducible gene StDS2 is delayed, but the expression of ETR1, encoding an ethylene receptor, is maintained for a longer period under the drought conditions than in the leaves of the non-treated, drought-stressed control plants. This result suggests that the ethylene-inducible gene expression remains suppressed in primed plants leading to a longer leaf life and increased tuber yield compared to the non-treated, drought-stressed plants. The priming effect of BABA in potato, however, is transient and reverts to an unprimed state within a few weeks.     

Urban airborne pollen in a semiarid environment

The present investigation was conducted to determine the pollen types and their quantities in the atmosphere of Obregón City (a semiarid region) and establish the relationship with meteorological parameters in 2008 and 2011. A bimodal pattern with peaks in dry warm (spring) and late rainy (autumn) seasons was observed. The highest monthly pollen indexes were observed in October 2008 and September 2011. Precipitation in 2008 was 2.6 times higher than in 2011, beginning in June in both years, and ending in November (2008) and September (2011). Main pollen types were Poaceae, Chenopodiaceae/Amaranthaceae, Asteraceae and Parkinsonia (the latter was dominant in the dry warm season). Statistical correlations (Spearman’s rank-order correlation p < 0.05) with meteorological parameters were performed. In both sampling years, relative humidity caused adverse effects on the atmospheric pollen content, while temperature, solar radiation and wind speed in the dry season were associated with increased pollen indexes. Compared to other studies of semiarid areas, the pollen index at Obregón is low, which is attributed to a relatively high humidity and to the large area of grain crops surrounding the city.