A palaeoparasitological analysis of rodent coprolites from the Cueva Huenul 1 archaeological site in Patagonia (Argentina)

The aim of the present study was to examine the parasite fauna present in rodent coprolites collected from Cueva Huenul 1 (CH1), northern Neuquén (Patagonia, Argentina), an archaeological site that provides stratified sequences of archaeological and palaeontological remains dating from the Late Pleistocene/Early Holocene Transition to the Late Holocene period. Twenty rodent coprolites collected from different sedimentary units from the site, with ages ranging from 13.844 ± 75-1.416 ± 37 years BP, were examined for parasites. Each coprolite was processed as a whole: rehydrated, homogenised, spontaneously sedimented and examined using light microscopy. The coprolites and the eggs of any parasites present were described, measured and photographed. In all, 158 parasite eggs were found in 10 coprolites. The faeces were positive for Viscachataenia quadrata Denegri, Dopchiz, Elissondo & Beveridge and Monoecocestus sp. Beddard (Cestoda: Anoplocephalidae) and for Heteroxynema (Cavioxyura) viscaciae Sutton & Hugot (Nematoda: Oxyuridae). The coprolites examined were tentatively attributed to Lagidium viscacia Molina (Mammalia, Rodentia, Caviomorpha, Chinchillidae). The life cycles of these parasites are discussed.     

Presence of Bartonella species in wild carnivores of northern Spain

The genus Bartonella was detected by PCR in 5.7% (12/212) of wild carnivores from Northern Spain. Based on hybridization and sequence analyses, Bartonella henselae was identified in a wildcat (Felis silvestris), Bartonella rochalimae in a red fox (Vulpes vulpes) and in a wolf (Canis lupus), and Bartonella sp. in badgers (Meles meles).     

Molecular characterization of three 3-ketosteroid-Δ(1)-dehydrogenase isoenzymes of Rhodococcus ruber strain Chol-4

Rhodococcus ruber strain Chol-4 isolated from a sewage sludge sample is able to grow on minimal medium supplemented with steroids, showing a broad catabolic capacity. This paper reports the characterization of three different 3-ketosteroid-Δ(1)-dehydrogenases (KstDs) in the genome of R. ruber strain Chol-4. The genome of this strain does not contain any homologues of a 3-keto-5α-steroid-Δ(4)-dehydrogenase (Kst4d or TesI) that appears in the genomes of Rhodococcus erythropolis SQ1 or Comamonas testosteroni. Growth experiments with kstD2 mutants, either a kstD2 single mutant, kstD2 double mutants in combination with kstD1 or kstD3, or the triple kstD1,2,3 mutant, proved that KstD2 is involved in the transformation of 4-androstene-3,17-dione (AD) to 1,4-androstadiene-3,17-dione (ADD) and in the conversion of 9α-hydroxy-4-androstene-3,17-dione (9OHAD) to 9α-hydroxy-1,4-androstadiene-3,17-dione (9OHADD). kstD2,3 and kstD1,2,3 R. ruber mutants (both lacking KstD2 and KstD3) did not grow in minimal medium with cholesterol as the only carbon source, thus demonstrating the involvement of KstD2 and KstD3 in cholesterol degradation. In contrast, mutation of kstD1 does not alter the bacterial growth on the steroids tested in this study and therefore, the role of this protein still remains unclear. The absence of a functional KstD2 in R. ruber mutants provoked in all cases an accumulation of 9OHAD, as a branch product probably formed by the action of a 3-ketosteroid-9α-hydroxylase (KshAB) on the AD molecule. Therefore, KstD2 is a key enzyme in the AD catabolism pathway of R. ruber strain Chol-4 while KstD3 is involved in cholesterol catabolism.     

Fatty acid-binding protein 4 impairs the insulin-dependent nitric oxide pathway in vascular endothelial cells

ABSTRACT: BACKGROUND: Recent studies have shown that fatty acid-binding protein 4 (FABP4) plasma levels are associated with impaired endothelial function in type 2 diabetes (T2D). In this work, we analysed the effect of FABP4 on the insulin-mediated nitric oxide (NO) production by endothelial cells in vitro. METHODS: In human umbilical vascular endothelial cells (HUVECs), we measured the effects of FABP4 on the insulin-mediated endothelial nitric oxide synthase (eNOS) expression and activation and on NO production. We also explored the impact of exogenous FABP4 on the insulin-signalling pathway (insulin receptor substrate 1 (IRS1) and Akt). RESULTS: We found that eNOS expression and activation and NO production are significantly inhibited by exogenous FABP4 in HUVECs. FABP4 induced an alteration of the insulin-mediated eNOS pathway by inhibiting IRS1 and Akt activation. These results suggest that FABP4 induces endothelial dysfunction by inhibiting the activation of the insulin-signalling pathway resulting in decreased eNOS activation and NO production. CONCLUSION: These findings provide a mechanistic linkage between FABP4 and impaired endothelial function in diabetes, which leads to an increased cardiovascular risk.     

Snakin/GASA proteins: Involvement in hormone crosstalk and redox homeostasis

Snakin/GASA proteins are widely distributed among plant species. They are expressed in different plant organs with high tissue and temporal specificity, and their subcellular localization varies among the different members. Interestingly, all of them maintain 12 cysteines of the C-terminus in highly conserved positions of the aminoacid sequences that are essential for their biochemical activity and probably responsible for their protein structure. Despite their common features, their functions are not completely elucidated and little is known about their mode of action. This review focuses on the current knowledge about this intriguing family of peptides and advances comprising gene regulation analyses, expression pattern studies and phenotypic characterization of mutants and transgenic plants. Furthermore, we discuss the roles of Snakin/GASA proteins in several aspects of plant development, plant responses to biotic or abiotic stress and their participation in hormone crosstalk and redox homeostasis.     

Secondary relaxations in supercooled and glassy sucrose-borate aqueous solutions

The dielectric relaxation spectra of concentrated aqueous solutions of sucrose-borate mixtures have been measured in the supercooled and glassy regions in the frequency range of 40Hz to 2MHz. The secondary (beta) relaxation process was analyzed in the temperature range 183-233K at water contents between 20 and 30wt%. The relaxation times were obtained, and the activation energy of that process was calculated. In order to assess the effect of borate on the relaxation of disaccharide-water mixtures, we also studied the dielectric behavior of sucrose aqueous solutions in the same range of temperatures and water contents. Our findings support the view that, beyond a water content of approximately 20wt%, the secondary relaxation of water-sucrose and water-sucrose-borate mixtures adopts a universal character that can be explained in terms of a simple exponential function of the temperature scaled by the glass transition temperature (T(g)). The behavior observed for water-sucrose and water-sucrose-borate mixtures is compared with previous results obtained in other water-carbohydrate systems.     

Effects of androgens on serum concentrations of gonadotropins and ovarian steroids in gilts

To examine how androgens affect endocrine events associated with increased ovulation rate, gilts were injected with androgen receptor agonists, an antagonist, or a combination of both. Blood samples were collected hourly from Day 13 to estrus (Day 0 = onset of estrus) coincident with gilts (n = 6 per treatment) receiving daily treatments of vehicle (corn oil), 10 mg of testosterone, 10 mg of 5 alpha-dihydrotestosterone (dihydrotestosterone), 1.5 g of flutamide (an androgen receptor antagonist), testosterone plus flutamide, or dihydrotestosterone plus flutamide. Treatment of gilts with testosterone or dihydrotestosterone alone increased (P < 0.05) concentrations of FSH in serum, and these effects were blocked by cotreatment with flutamide. Estradiol-17beta and androstenedione concentrations in serum were increased (P < 0.05) at 2 h after injection of testosterone or testosterone plus flutamide but not after dihydrotestosterone treatment, probably because of the role of testosterone as a substrate for estradiol-17beta and androstenedione synthesis. There were no effects of the six treatments on serum concentrations of progesterone during luteolysis, but treating gilts with testosterone shortened (P < 0.05) the proestrous period. Total embryonic loss by Day 11 in gilts treated with dihydrotestosterone was reversed when gilts were cotreated with dihydrotestosterone plus flutamide. Results of this experiment indicated that androgen actions both increased FSH secretion and reduced embryonic survival by a mechanism(s) dependent on the androgen receptor.     

Unraveling the mechanisms of tryptophan fluorescence quenching in the triosephosphate isomerase from Giardia lamblia

In the native state several proteins exhibit a quenching of fluorescence of their tryptophans. We studied triosephosphate isomerase from Giardia lamblia (GlTIM) to dissect the mechanisms that account for the quenching of fluorescence of its Trp. GlTIM contains four Trp per monomer (Trp75, Trp162, Trp173, and Trp196) distributed throughout the 3D structure. The fluorescence of the denatured enzyme is 3-fold higher than that of native GlTIM. To ascertain the origin of this phenomenon, single and triple mutants of Trp per Phe were made. The intrinsic fluorescence was determined, and the data were interpreted on the basis of the crystal structure of the enzyme. Our data show that the fluorescence of all Trp residues is quenched through two different mechanisms. In one, fluorescence is quenched by aromatic-aromatic interactions due to the proximity and orientation of the indole groups of Trp196 and Trp162. The magnitude of the quenching of fluorescence in Trp162 is higher than in the other three Trp. Fluorescence quenching is also due to energy transfer to the charged residues that surround Trp 75, 173 and 196. Further analysis of the fluorescence of GlTIM showed that, among TIMs from other parasites, Trp at position 12 exhibits rather unique properties.     

Modulation of inflammatory responses by diterpene acids from Helianthus annuus L

Fractionation of a petroleum ether extract of Helianthus annuus L. led to the isolation of three diterpene acids: grandiflorolic, kaurenoic and trachylobanoic acids. These compounds were studied for potential anti-inflammatory activity on the generation of inflammatory mediators in lipopolysaccharide (LPS)-activated RAW 264.7 macrophages. At non-toxic concentrations, these compounds reduced, in a concentration-dependent manner nitric oxide (NO), prostaglandin E₂ (PGE₂) and tumor necrosis factor (TNF-α) production, as well as expression of inducible nitric oxide synthase (NOS-2) and cyclooxygenase-2 (COX-2).All diterpenoids displayed significant in vivo anti-inflammatory activity and suppressed the 12-O-tetradecanoylphorbol-13-acetate (TPA)-mouse ear edema. In addition, inhibition of myeloperoxidase (MPO) activity, an index of cellular infiltration, was observed.In summary, our results suggest that the inhibition of the expression of NOS-2, COX-2 and the release of inflammatory cytokines, is responsible for the anti-inflammatory effects of the diterpenoids isolated from H. annuus L. which likely contributes to the pharmacological action of sunflower.     

Detection of HSV type-1 and type-2 IgG using an in vitro PCA based homogeneous immunoassay

Enzyme immunoassays (EIAs) are widely used in the clinical laboratory and research institutes for the detection of biologically relevant analytes. Almost all EIAs are heterogeneous in nature and require multiple steps of process. In contrast, homogeneous immunoassays (HA) offer a simplified one-step approach with a number of potential advantages over contemporary heterogeneous EIAs such as higher throughput and greater clinical utility. Utilizing TEM-1 β-lactamase as a reporter enzyme, we have developed HAs based on in vitro protein fragment complementation (PCA) for the detection of antibodies and potentially be used for antigens or other biomarkers. In this proof-of-principle study we demonstrate the successful in vitro differentiation of anti-herpes simplex virus (HSV) type-1 and type-2 Immunoglobulin G (IgG) in human serum with high sensitivity and specificity.