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| | 1. |
2012 Jan 5 |
Influence of sub-lethal antioxidant doses, water potential and temperature on growth, sclerotia, aflatoxins and aflD (=nor-1) expression by Aspergillus flavus RCP08108.
Passone MA, Rosso LC, Etcheverry M
Microbiol Res. 2012 Jan 5; [Epub ahead of print]
Abstract
Effects of interacting conditions of sub-lethal levels of antioxidants, water potential (Ψ) and temperature were evaluated on growth, sclerotial characteristics, aflatoxin B(1) (AFB(1)) production and aflD (=nor-1) gene expression by Aspergillus flavus strain RCP08108. These studies were carried out on peanut meal extract agar osmotically modified to -2.8,-7.1, -9.9 and -16.0MPa and incubated at 28 and 20°C. The food grade antioxidants added were butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) at (1+1mM-M1) and (5+5mM-M2). To relate the aflD expression after toxigenic A. flavus grew under interacting stress conditions, real-time PCR was used. Antioxidant mixtures caused a higher and significant (p<0.001) reduction in growth rate. The major impact on size and volume sclerotia was produced by Ψ; followed by antioxidant mixtures. High AFB(1) levels were observed in response to the M1 applied at -7.1MPa. Induction of the aflD gene was observed in response to the M1 treatment at -2.8, -7.1 and -9.9MPa; but significant decreases of AFB(1) production and aflD transcripts were observed; when the fungus grew in the presence of the M2 treatment. These results showed that it is necessary to apply food-grade antioxidants into the peanut storage system at levels higher than 5mM. This is an important tool to avoid sub-lethal antioxidant doses that can lead to fungal growth, increase resistance structures, and stimulate aflD gene expression and AFB(1) accumulation in this substrate.
[Pubmed: 22227105]
| | 2. |
2012 Mar 28 |
Anthelmintic resistance in sheep farms: Update of the situation in the American continent.
Torres-Acosta JF, Mendoza-de-Gives P, Aguilar-Caballero AJ, Cuéllar-Ordaz JA
Vet Parasitol. 2012 Mar 28; [Epub ahead of print]
Abstract
The present paper reviews the frequency of anthelmintic resistance in sheep farms in different countries of the American continent and describes some aspects that might influence the trend in sheep farms. The situation of anthelmintic resistance in sheep farms has been explored mainly in south of the continent (Argentina, Brazil and Uruguay) where sheep farming is an important industry. In those three countries, as well as in Paraguay, the first comprehensive surveys of anthelmintic resistance were performed among countries in the continent, which showed evidence of high frequency of sheep farms with anthelmintic resistance. Today, it is common to find sheep flocks with multiple-resistant worms. In North and Central America, a similar situation has been reported in sheep farms in the south of the United States of America, parts of Mexico and Costa Rica. On the other hand, other areas of the continent show low frequency of farms with anthelmintic resistance. From many areas no results have been published regarding situation on anthelmintic resistance or, alternatively, published results have received limited dissemination. Although the diagnosis of anthelmintic resistance is important for decision making of helminth management/control at the farm level, this is still an aspiration rather than a reality. For decades, researchers working on anthelmintic resistance in the American continent have expressed the need to change farmers' attitudes towards anthelmintic drugs. A common advice has been to check the anthelmintic drug efficacy regularly and reduce the dependence on these with alternative control measures. In spite of such advice, the challenge to stop/delay the advancement of anthelmintic resistance against the available anthelmintic drugs is still present. The evidence suggests that anthelmintic resistance is a growing phenomenon in the American continent. The situation described might be the tip of the iceberg, as anthelmintic resistance is still largely under-diagnosed. Hence, a different approach to tackle the advancement of anthelmintic resistance in sheep farms must be found. Awareness of farmers on the importance of diagnosis of anthelmintic resistance is not enough. Technical support schemes that provide the diagnostic service cheaply and timely must be implemented together with the research aiming at the adoption of control methods to reduce the dependence on conventional anthelmintic drugs. Unless these elements are readily available for producers, the negative consequences of anthelmintic resistance on sheep farming in America will continue to worsen with time.
[Pubmed: 22520233]
| | 3. |
2012 Jul 3 |
The sylvatic transmission cycle of Trypanosoma cruzi in a rural area in the humid Chaco of Argentina.
Alvarado-Otegui JA, Ceballos LA, Orozco MM, Enriquez GF, Cardinal MV, Cura C, Schijman AG, Kitron U, Gürtler RE
Acta Trop. 2012 Jul 3; [Epub ahead of print]
Abstract
Little is known about the sylvatic transmission cycle of Trypanosoma cruzi in the Gran Chaco ecoregion. We conducted surveys to identify the main sylvatic hosts of T. cruzi, parasite discrete typing units and vector species involved in Pampa del Indio, a rural area in the humid Argentinean Chaco. A total of 44 mammals from 14 species were captured and examined for infection by xenodiagnosis and polymerase chain reaction amplification of the hyper-variable region of kinetoplast DNA minicircles of T. cruzi (kDNA-PCR). Ten (22.7%) mammals were positive by xenodiagnosis or kDNA-PCR. Four of 11 (36%) Didelphis albiventris (white-eared opossums) and six of nine (67%) Dasypus novemcinctus (nine-banded armadillos) were positive by xenodiagnosis and or kDNA-PCR. Rodents, other armadillo species, felids, crab-eating raccoons, hares and rabbits were not infected. Positive animals were highly infectious to the bugs that fed upon them as determined by xenodiagnosis. All positive opossums were infected with T. cruzi I and all positive nine-banded armadillos with T. cruzi III. Extensive searches in sylvatic habitats using 718 Noireau trap-nights only yielded Triatoma sordida whereas no bug was collected in 26 light-trap nights. Four armadillos or opossums fitted with a spool-and-line device were successfully tracked to their refuges; only one Panstrongylus geniculatus was found in an armadillo burrow. No sylvatic triatomine was infected with T. cruzi by microscopical examination or kDNA-PCR. Our results indicate that two independent sylvatic transmission cycles of T. cruzi occur in the humid Chaco. The putative vectors of both cycles need to be identified conclusively.
[Pubmed: 22771688]
| | 4. |
2012 Jun 19 |
Acute behavioural responses to nicotine and nicotine withdrawal syndrome are modified in GABA(B1) knockout mice.
Varani AP, Moutinho LM, Bettler B, Balerio GN
Neuropharmacology. 2012 Oct;63(5):863-72. Epub 2012 Jun 19.
Abstract
Nicotine is the main active component of tobacco, and has both acute and chronic pharmacological effects that can contribute to its abuse potential in humans. The aim of the present study was to evaluate a possible role of GABA(B) receptors in acute and chronic responses to nicotine administration, by comparing GABA(B1) knockout mice and their wild-type littermates. In wild-type mice, acute nicotine administration (0.5, 1, 3 and 6 mg/kg, sc) dose-dependently decreased locomotor activity, and induced antinociceptive responses in the tail-immersion and hot-plate tests. In GABA(B1) knockout mice, the hypolocomotive effect was observed only with the highest dose of nicotine, and the antinociceptive responses in both tests were significantly reduced in GABA(B1) knockout mice compared to their wild-type littermate. Additionally, nicotine elicited anxiolytic- (0.05 mg/kg) and anxiogenic-like (0.8 mg/kg) responses in the elevated plus-maze test in wild-type mice, while selectively the anxiolytic-like effect was abolished in GABA(B1) knockout mice. We further investigated nicotine withdrawal in mice chronically treated with nicotine (25 mg/kg/day, sc). Mecamylamine (1 mg/kg, sc) precipitated several somatic signs of nicotine withdrawal in wild-type mice. However, signs of nicotine withdrawal were missing in GABA(B1) knockout mice. Finally, there was a decreased immunoreactivity of Fos-positive nuclei in the bed nucleus of the stria terminalis, basolateral amygdaloid nucleus and hippocampal dentate gyrus in abstinent wild-type but not in GABA(B1) knockout mice. These results reveal an interaction between the GABA(B) system and the neurochemical systems through which nicotine exerts its acute and long-term effects.
[Pubmed: 22727822]
| | 5. |
2012 Jun 19 |
Photochemical fate of a mixture of emerging pollutants in the presence of humic substances.
Carlos L, Mártire DO, Gonzalez MC, Gomis J, Bernabeu A, Amat AM, Arques A
Water Res. 2012 Oct 1;46(15):4732-40. Epub 2012 Jun 19.
Abstract
The photodegradation of a mixture of the emerging pollutants (EPs) clofibric acid, amoxicillin, acetamiprid, acetaminophen, carbamazepine, and caffeine was studied under irradiation with a xenon lamp. The quantum efficiencies of the EPs were determined when irradiated individually. Experiments with the mixture of the EPs showed that indirect photoprocesses attributable to interaction between EPs can either enhance the photodegradation rate by photosensitization or decrease it by quenching processes. The addition of humic substances (HS) to the solutions resulted in an increase of indirect photoprocesses with higher effects on acetaminophen and carbamazepine; this was more remarkable when a filter was used to cut off radiation in the range 280-295 nm. Experiments carried out with chemical probes indicated that the triplet excited states of HS play a major role in the photosensitization process, although the contribution of other species cannot be completely ruled out. Additionally, V. fischeri toxicity tests showed a synergistic effect produced by the mixture of EPs before irradiation. Photodegradation resulted in an enhanced toxicity of the solution at the initial steps of the process, which was associated both with synergistic effects and with the formation of toxic photodegradation by-products of clofibric acid.
[Pubmed: 22766461]
| | 6. |
2012 May 22 |
Concomitant tumor resistance.
Chiarella P, Bruzzo J, Meiss RP, Ruggiero RA
Cancer Lett. 2012 Nov 28;324(2):133-41. Epub 2012 May 22.
Abstract
Concomitant tumor resistance (CR) is a phenomenon in which a tumor-bearing host is resistant to the growth of secondary tumor implants. This phenomenon has been described in human and animal systems and it can be generated by both immunogenic and non-immunogenic tumors. The relevance of CR to the mechanisms of metastases control has been highlighted by numerous observations showing that the removal of human and murine tumors may be followed by an abrupt increase in metastatic growth, suggesting that a primary tumor may exert a controlling action on its metastases which could be considered as secondary tumor implants developed spontaneously during the primary tumor growth. A more profound understanding of the different mechanisms claimed to be associated with the phenomenon of CR could contribute to develop new and more harmless means to manage malignant diseases, especially by limiting the development of metastases that arise after resection of primary tumors or after other stressors that may promote the escape of metastases from dormancy.
[Pubmed: 22634498]
| | 7. |
2012 May 16 |
Viscosity of supercooled aqueous glycerol solutions, validity of the Stokes-Einstein relationship, and implications for cryopreservation.
Trejo González JA, Paula Longinotti M, Corti HR
Cryobiology. 2012 Oct;65(2):159-62. Epub 2012 May 16.
Abstract
The viscosity of supercooled glycerol aqueous solutions, with glycerol mass fractions between 0.70 and 0.90, have been determined to confirm that the Avramov-Milchev equation describes very well the temperature dependence of the viscosity of the binary mixtures including the supercooled regime. On the contrary, it is shown that the free volume model of viscosity, with the parameters proposed in a recent work (He, Fowler, Toner, J. Appl. Phys. 100 (2006) 074702), overestimates the viscosity of the glycerol-rich mixtures at low temperatures by several orders of magnitude. Moreover, the free volume model for the water diffusion leads to predictions of the Stokes-Einstein product, which are incompatible with the experimental findings. We conclude that the use of these free volume models, with parameters obtained by fitting experimental data far from the supercooled and glassy regions, lead to incorrect predictions of the deterioration rates of biomolecules, overestimating their life times in these cryopreservation media.
[Pubmed: 22609516]
| | 8. |
2012 May 08 |
Nuclear localization of heme oxygenase-1 is associated with tumor progression of head and neck squamous cell carcinomas.
Gandini NA, Fermento ME, Salomón DG, Blasco J, Patel V, Gutkind JS, Molinolo AA, Facchinetti MM, Curino AC
Exp. Mol. Pathol. 2012 Oct;93(2):237-45. Epub 2012 May 08.
Abstract
The expression of heme oxygenase-1 (HO-1) was shown to be increased in multiple tumors compared with their surrounding healthy tissues and was also observed to be up-regulated in oral squamous cell carcinomas (OSCC). However, conflicting results were obtained and little information is available regarding HO-1 significance in head and neck squamous cell carcinoma (HNSCC). Therefore, the aim of the present study was to perform a wide screening of HO-1 expression in a large collection of human primary HNSCCs and to correlate the results with clinical and pathological parameters. For this purpose, we investigated the expression of this protein by immunohistochemistry (IHC) in tissue microarrays (TMAs) of HNSCC and in an independent cohort of paraffin-embedded tumor specimens. HO-1 expression was further validated by real-time qPCR performed on selected laser capture-microdissected (LCM) oral tissue samples. Both the number of HO-1-positive samples and HO-1 immunoreactivity in the cancerous tissues were significantly higher than those in the non-tumor tissues. These results were confirmed at the mRNA level. Interestingly, HO-1 localization was observed in the nucleus, and the rate of nuclear HO-1 in HNSCC was higher than that in non-malignant tissues. Nuclear HO-1 was observed in HNSCC cell lines and increased even further following hemin treatment. Analysis of HO-1 expression and sub-cellular localization in a mouse model of squamous cell carcinoma (SCC) and in human HNSCC revealed that nuclear HO-1 increases with tumor progression. Taken together, these results demonstrate that HO-1 is up-regulated in HNSCC and that nuclear localization of HO-1 is associated with malignant progression in this tumor type.
[Pubmed: 22580187]
| | 9. |
2012 Apr 14 |
Application of bacteriocinogenic Enterococcus mundtii CRL35 and Enterococcus faecium ST88Ch in the control of Listeria monocytogenes in fresh Minas cheese.
Vera Pingitore E, Todorov SD, Sesma F, Gombossy de Melo Franco BD
Food Microbiol. 2012 Oct;32(1):38-47. Epub 2012 Apr 14.
Abstract
Several strains of Enterococcus spp. are capable of producing bacteriocins with antimicrobial activity against important bacterial pathogens in dairy products. In this study, the bacteriocins produced by two Enterococcus strains (Enterococcus mundtii CRL35 and Enterococcus faecium ST88Ch), isolated from cheeses, were characterized and tested for their capability to control growth of Listeria monocytogenes 426 in experimentally contaminated fresh Minas cheese during refrigerated storage. Both strains were active against a variety of pathogenic and non-pathogenic microorganisms and bacteriocin absorption to various L. monocytogenes, Enterococcus faecalis ATCC 19443 and Lactobacillus sakei ATCC 15521 varied according to the strain and the testing conditions (pH, temperature, presence of salts and surfactants). Growth of L. monocytogenes 426 was inhibited in cheeses containing E. mundtii CRL35 up to 12 days at 8 °C, evidencing a bacteriostatic effect. E. faecium ST88Ch was less effective, as the bacteriostatic affect occurred only after 6 days at 8 °C. In cheeses containing nisin (12.5 mg/kg), less than one log reduction was observed. This research underlines the potential application of E. mundtii CRL35 in the control of L. monocytogenes in Minas cheese.
[Pubmed: 22850372]
| | 10. |
2012 Sep 15 |
Characterization of lipid A profiles from Shigella flexneri variant X lipopolysaccharide.
Casabuono AC, van der Ploeg CA, Rogé AD, Bruno SB, Couto AS
Rapid Commun. Mass Spectrom. 2012 Sep 15;26(17):2011-20.
Abstract
In developing countries, Shigella flexneri (Sf) is the major causative agent of the endemic shigellosis (bacillary dysentery) responsible annually for one million fatalities mostly among infants. Lipopolysaccharides (LPSs) are characteristic components of the outer membrane of the overwhelming majority of Gram-negative bacteria. Since lipid A is essential for the viability of the Gram-negative bacteria, it is subject to extensive chemical studies with new analytical techniques.
[Pubmed: 22847700]
| | 11. |
2012 Jul 23 |
Photosensitizing properties of biopterin and its photoproducts using 2'-deoxyguanosine 5'-monophosphate as an oxidizable target.
Serrano MP, Lorente C, Morán Vieyra FE, Borsarelli CD, Thomas AH
Phys Chem Chem Phys. 2012 Sep 7;14(33):11657-65. Epub 2012 Jul 23.
Abstract
UV-A radiation (320-400 nm) induces damage to the DNA molecule and its components through photosensitized reactions. Biopterin (Bip) and its photoproducts 6-formylpterin (Fop) and 6-carboxypterin (Cap) accumulate in the skin of human beings suffering from vitiligo, a depigmentation disorder where the protection against UV radiation fails because of the lack of melanin. This study was aimed to evaluate the photosensitizing properties of oxidized pterins present in the skin and to elucidate the mechanisms involved in the photosensitized oxidation of purine nucleotides by pterins in vitro. For this purpose, steady-state and time-resolved experiments in acidic (pH 5.0-5.8) aqueous solution were performed using Bip, Fop and Cap as photosensitizers and the nucleotide 2'-deoxyguanosine 5'-monophosphate (dGMP) as an oxidizable target. The three pterin derivatives are able to photosensitize dGMP, being Fop the most efficient sensitizer. The reactions proceed through two competing pathways: (1) electron transfer from dGMP to triplet excited-state of pterins (type I mechanism) and (2) reaction of dGMP with (1)O(2) produced by pterins (type II mechanism). Kinetic analysis revealed that the electron transfer pathway is the main mechanism and the interaction of dGMP with the triplet excited-state of pterins and the formation of the corresponding dGMP radicals were demonstrated by laser flash photolysis experiments. The biological implications of the results obtained are also discussed.
[Pubmed: 22825359]
| | 12. |
2012 May 30 |
Host-parasite coevolution beyond the nestling stage? Mimicry of host fledglings by the specialist screaming cowbird.
De Mársico MC, Gantchoff MG, Reboreda JC
Proc. Biol. Sci. 2012 Sep 7;279(1742):3401-8. Epub 2012 May 30.
Abstract
Egg mimicry by obligate avian brood parasites and host rejection of non-mimetic eggs are well-known textbook examples of host-parasite coevolution. By contrast, reciprocal adaptations and counteradaptations beyond the egg stage in brood parasites and their hosts have received less attention. The screaming cowbird (Molothrus rufoaxillaris) is a specialist obligate brood parasite whose fledglings look identical to those of its primary host, the baywing (Agelaioides badius). Such a resemblance has been proposed as an adaptation in response to host discrimination against odd-looking young, but evidence supporting this idea is scarce. Here, we examined this hypothesis by comparing the survival rates of young screaming cowbirds and non-mimetic shiny cowbirds (Molothrus bonariensis) cross-fostered to baywing nests and quantifying the similarity in plumage colour and begging calls between host and cowbird fledglings. Shiny cowbirds suffered higher post-fledging mortality rates (83%) than screaming cowbirds (0%) owing to host rejection. Visual modelling revealed that screaming cowbirds, but not shiny cowbirds, were indistinguishable from host young in plumage colour. Similarly, screaming cowbirds matched baywings' begging calls more closely than shiny cowbirds. Our results strongly support the occurrence of host fledgling mimicry in screaming cowbirds and suggest a role of visual and vocal cues in fledgling discrimination by baywings.
[Pubmed: 22648157]
| | 13. |
2012 Jun 01 |
Reconsolidation involves histone acetylation depending on the strength of the memory.
Federman N, Fustiñana MS, Romano A
Neuroscience. 2012 Sep 6;219:145-56. Epub 2012 Jun 01.
Abstract
Gene expression is a necessary step for memory re-stabilization after retrieval, a process known as reconsolidation. Histone acetylation is a fundamental mechanism involved in epigenetic regulation of gene expression and has been implicated in memory consolidation. However, few studies are available in reconsolidation, all of them in vertebrate models. Additionally, the recruitment of histone acetylation as a function of different memory strengths has not been systematically analyzed before. Here we studied the role of histone acetylation in reconsolidation using a well-characterized memory model in invertebrate, the context-signal memory in the crab Chasmagnathus. Firstly, we found an increase in histone H3 acetylation 1h after memory reactivation returning to basal levels at 3h. Strikingly, this increment was only detected during reconsolidation of a long-term memory induced by a strong training of 30 trials, but not for a short-term memory formed by a weak training of five trials or for a long-term memory induced by a standard training of 15 trials. Furthermore, we showed that a weak memory which was enhanced during consolidation by histone deacetylases inhibition, also recruited histone H3 acetylation in reconsolidation as the strong training does. Accordingly, we found the first evidence that the administration of a histone acetyl transferase inhibitor during memory reconsolidation impairs long-term memory re-stabilization. Finally, we found that strong training memory, at variance with the standard training memory, was resistant to extinction, indicating that such strong training induced in fact a stronger memory. In conclusion, the results presented here support that the participation of histone acetylation during reconsolidation is an evolutionary conserved feature and constitutes a specific molecular characteristic of strong memories.
[Pubmed: 22659565]
| | 14. |
2012 Jul 24 |
The effect of airborne particles and weather conditions on pediatric respiratory infections in Cordoba, Argentine.
Amarillo AC, Carreras HA
Environ Pollut. 2012 Jul 24;170C:217-221. Epub 2012 Jul 24.
Abstract
We studied the effect of estimated PM(10) on respiratory infections in children from Cordoba, Argentine as well as the influence of weather factors, socio-economic conditions and education. We analyzed upper and lower respiratory infections and applied a time-series analysis with a quasi-Poisson distribution link function. To control for seasonally varying factors we fitted cubic smoothing splines of date. We also examined community-specific parameters and differences in susceptibility by sex. We found a significant association between particles and respiratory infections. This relationship was affected by mean temperature, atmospheric pressure and wind speed. These effects were stronger in fall, winter and spring for upper respiratory infections while for lower respiratory infections the association was significant only during spring. Low socio-economic conditions and low education levels increased the risk of respiratory infections. These findings add useful information to understand the influence of airborne particles on children health in developing countries.
[Pubmed: 22835501]
| | 15. |
2012 Nov 01 |
The actin cytoskeleton participates in the early events of autophagosome formation upon starvation induced autophagy.
Aguilera MO, Berón W, Colombo MI
Autophagy. 2012 Nov 1;8(11). Epub 2012 Nov 01.
Abstract
Autophagy is a process by which cytoplasmic material is sequestered in a double-membrane vesicle destined for degradation. Nutrient deprivation stimulates the pathway and the number of autophagosomes in the cell increases in response to such stimulus. In the current report we have demonstrated that actin is necessary for starvation-mediated autophagy. When the actin cytoskeleton is depolymerized, the increase in autophagic vacuoles in response to the starvation stimulus was abolished without affecting maturation of remaining autophagosomes. In addition, actin filaments colocalized with ATG14, BECN1/Beclin1 and PtdIns3P-rich structures, and some of them have a typical omegasome shape stained with the double FYVE domain or ZFYVE1/DFCP1. In contrast, no major colocalization between actin and ULK1, ULK2, ATG5 or MAP1LC3/LC3 was observed. Taken together, our data indicate that actin has a role at very early stages of autophagosome formation linked to the PtdIns3P generation step. In addition, we have found that two members of the Rho family of proteins, RHOA and RAC1 have a regulatory function on starvation-mediated autophagy, but with opposite roles. Indeed, RHOA has an activatory role whereas Rac has an inhibitory one. We have also found that inhibition of the RHOA effector ROCK impaired the starvation-mediated autophagic response. We propose that actin participates in the initial membrane remodeling stage when cells require an enhanced rate of autophagosome formation, and this actin function would be tightly regulated by different members of the Rho family.
[Pubmed: 22863730]
| | 16. |
2012 Aug 7 |
New insight into the electrochemical desorption of alkanethiol SAMs on gold.
Pensa E, Vericat C, Grumelli D, Salvarezza RC, Park SH, Longo GS, Szleifer I, Méndez De Leo LP
Phys Chem Chem Phys. 2012 Aug 7; [Epub ahead of print]
Abstract
A combination of Polarization Modulation Infrared Reflection Absorption Spectroscopy (PMIRRAS) under electrochemical control, Electrochemical Scanning Tunneling Microscopy (ECSTM) and Molecular Dynamics (MD) simulations has been used to shed light on the reductive desorption process of dodecanethiol (C12) and octadecanethiol (C18) SAMs on gold in aqueous electrolytes. Experimental PMIRRAS, ECSTM and MD simulations data for C12 desorption are consistent with formation of randomly distributed micellar aggregates stabilized by Na(+) ions, coexisting with a lying-down phase of molecules. The analysis of pit and Au island coverage before and after desorption is consistent with the thiolate-Au adatoms models. On the other hand, PMIRRAS and MD data for C18 indicate that the desorbed alkanethiolates adopt a Na(+) ion-stabilized bilayer of interdigitated alkanethiolates, with no evidence of lying down molecules. MD simulations also show that both the degree of order and tilt angle of the desorbed alkanethiolates change with the surface charge on the metal, going from bilayers to micelles. These results demonstrate the complexity of the alkanethiol desorption in the presence of water and the fact that chain length and counterions play a key role in a complex structure.
[Pubmed: 22870508]
| | 17. |
2012 Aug 09 |
A new species of Colobomatus (Copepoda, Phylichthyidae) parasitic on Mullus argentinae (Perciformes, Mullidae) from South American Atlantic coast.
Pereira AN, Timi JT, Lanfranchi AL, Luque JL
Acta Parasitol. 2012 Sep;57(3):323-8. Epub 2012 Aug 09.
Abstract
A new species of Colobomatus Hesse, 1873 is described from pores of the cephalic sensory system and nostrils of Argentine goatfish, Mullus argentinae Hubbs et Marini, 1933 (Perciformes: Mullidae), living along the southwestern Atlantic coast. The fish were collected at different latitudes, stretching from the State of Rio de Janeiro in the north, through Santa Catarina, Rio Grande do Sul (Brazil) to of Mar del Plata (Argentina) in the south. The prevalence of the infection ranged from 42% through 84%. The new species look alike to two other species, parasites of mullids (C. steenstrupi and C. mulli) particularly in the body shape and the number, shape, and ornamentation of cephalic, thoracic, and genital processes. The new species, however, can be readily distinguished by having the central cephalic process shorter than lateral ones, the later being bilobed at tip forked, and a relatively larger abdomen. Furthermore, C. steenstrupi possesses relatively wider trunk processes with rounded tips, a short abdominal dorsal process, and attains a larger size (up to 3.6 mm). C. mulli also differs by having all body processes with forked tips, and relatively shorter sixth thoracic somite and abdominal segments 1-3. This is the third record of a species of Colobomatus in South American Atlantic waters.
[Pubmed: 22875682]
| | 18. |
2012 Dec 1 |
Apocynin administration prevents the changes induced by a fructose-rich diet on rat liver metabolism and the antioxidant system.
Castro MC, Francini F, Schinella G, Caldiz CI, Zubiría MG, Gagliardino JJ, Massa ML
Clin. Sci. 2012 Dec 1;123(12):681-92.
Abstract
In the present study, we investigated the role of NADPH oxidase in F (fructose)-rich-diet-induced hepatic OS (oxidative stress) and metabolic changes, and their prevention by apocynin co-administration. Wistar rats were fed for 21 days on (i) a control diet, (ii) a control diet plus 10% F in the drinking water, (iii) a control diet with apocynin in the drinking water (CA) and (iv) F plus apocynin in the drinking water (FA). Glycaemia, triglyceridaemia, NEFAs (non-esterified fatty acids) and insulinaemia were determined. In the liver, we measured (i) NADPH oxidase activity, and gene and protein expression; (ii) protein carbonyl groups, GSH and TBARSs (thiobarbituric acid-reactive substances); (iii) catalase, CuZn-SOD (superoxide dismutase) and Mn-SOD expression; (iv) liver glycogen and lipid content; (v) GK (glucokinase), G6Pase (glucose-6-phosphatase) and G6PDH (glucose-6-phosphate dehydrogenase) activities; (vi) FAS (fatty acid synthase), GPAT (glycerol-3-phosphate acyltransferase), G6Pase and G6PDH, IL-1β (interleukin-1β), PAI-1 (plasminogen-activator inhibitor-1) and TNFα (tumour necrosis factor α) gene expression; and (vii) IκBα (inhibitor of nuclear factor κB α) protein expression. F-fed animals had high serum TAG (triacylglycerol), NEFA and insulin levels, high liver NADPH oxidase activity/expression, increased OS markers, reduced antioxidant enzyme expression, and increased glycogen, TAG storage and GK, G6Pase and G6PDH activities. They also had high G6Pase, G6PDH, FAS, GPAT, TNFα and IL-1β gene expression and decreased IκBα expression. Co-administration of apocynin to F-fed rats prevented the development of most of these abnormalities. In conclusion, NADPH oxidase plays a key role in F-induced hepatic OS production and probably also in the mechanism of liver steatosis, suggesting its potential usefulness for the prevention/treatment of T2DM (Type 2 diabetes mellitus).
[Pubmed: 22738259]
| | 19. |
2012 Jun 26 |
Preparation of controlled gold nanoparticle aggregates using a dendronization strategy.
Paez JI, Coronado EA, Strumia MC
J Colloid Interface Sci. 2012 Oct 15;384(1):10-21. Epub 2012 Jun 26.
Abstract
In this work, a dendronization strategy was used to control interparticle spacing and the optical properties of gold nanoparticle (NP) aggregates in aqueous media. To achieve this goal, two dendritic disulfides bearing different functionalities on their periphery were synthesized and used as ligands to dendronize gold NPs. The dendronized NPs then undergo aggregation; this process was followed by UV-vis spectroscopy, dynamic light scattering (DLS), and transmission electronic microscopy (TEM) measurements and correlated with Generalized Mie Theory electrodynamics calculations. For comparison, NP functionalization was also studied using a nondendritic ligand. It was found that the use of dendritic disulfides allows for the preparation of controlled NP aggregates. This study demonstrates how different dendronization parameters, such as disulfide concentration, temperature, time and nature of the ligand (dendritic vs nondendritic), determine the control exerted over the size and stability of the NP aggregates.
[Pubmed: 22818798]
| | 20. |
2012 Jul 20 |
Effects of heavy metal concentrations (Cd, Zn and Pb) in agricultural soils near different emission sources on quality, accumulation and food safety in soybean [Glycine max (L.) Merrill].
Salazar MJ, Rodriguez JH, Nieto GL, Pignata ML
J. Hazard. Mater. 2012 Sep 30;233-234:244-53. Epub 2012 Jul 20.
Abstract
Argentina is one of the major producers of soybean in the world, this generates a high global demand for this crop leading to find it everywhere, even close to human activities involving pollutant emissions. This study evaluated heavy metal content, the transfer of metals and its relation to crop quality, and the toxicological risk of seed consumption, through soil and soybean sampling. The results show that concentrations of Pb and Cd in soils and soybeans at several sites were above the maximum permissible levels. The heavy metal bioaccumulation depending on the rhizosphere soil compartment showed significant and high regression coefficients. In addition, the similar behavior of Cd and Zn accumulation by plants reinforces the theory of other studies indicating that these metals are incorporated into the plant for a common system of transport. On the other hand, the seed quality parameters did not show a clear pattern of response to metal bioacumulation. Taken together, our results show that soybeans grown nearby to anthropic emission sources might represent a toxicological hazard for human consumption in a potential Chinese consumer. Hence, further studies should be carried out taking into account the potential negative health effects from the consumption of soybeans (direct or indirect through consumption of meat from cattle) in these conditions.
[Pubmed: 22835772]
| | 21. |
2012 Aug 09 |
Ornithodoros quilinensis sp. nov. (Acari, Argasidae), a new tick species from the Chacoan region in Argentina.
Venzal JM, Nava S, Mangold AJ, Mastropaolo M, Casás G, Guglielmone AA
Acta Parasitol. 2012 Sep;57(3):329-36. Epub 2012 Aug 09.
Abstract
Ornithodoros quilinensis sp. nov. (Acari: Argasidae) is described from larvae collected on the small rodents Graomys centralis (Cricetidae: Sigmodontinae) in Argentina. The diagnostic characters for this new species are a combination of small size (520-540 μm), a dorsal plate oval in shape with a length of approximately 200 μm, 14 pairs of dorsal setae, hypostome short and narrower at the base (length from Ph(1) to apex 133 μm (120-141)) with dental formula 2/2 and apex blunt, and the capsule of the Haller's organ irregular in shape and without reticulations. The analysis of the 16S rDNA sequences available for the genus Ornithodoros indicate that, phylogenetically, O. quilinensis represents an independent lineage only related to a Bolivian tick species of the genus Ornithodoros yet not formally described.
[Pubmed: 22875683]
| | 22. |
2012 Jul 10 |
Role of mu, delta and kappa opioid receptors in ethanol-reinforced operant responding in infant rats.
Miranda-Morales RS, Spear NE, Nizhnikov ME, Molina JC, Abate P
Behav. Brain Res. 2012 Oct 1;234(2):267-77. Epub 2012 Jul 10.
Abstract
We recently observed that naloxone, a non-specific opioid antagonist, attenuated operant responding to ethanol in infant rats. Through the use of an operant conditioning technique, we aimed to analyze the specific participation of mu, delta, and kappa opioid receptors on ethanol reinforcement during the second postnatal week. In Experiment 1, infant rats (PDs 14-17) were trained to obtain 5, 7.5, 10, or 15% ethanol, by operant nose-poking. Experiment 2 tested blood ethanol levels (BELs) attained by operant behavior. In Experiment 3, at PDs 16-18, rats received CTOP (mu antagonist: 0.1 or 1.0mg/kg), naltrindole (delta antagonist: 1.0 or 5.0mg/kg) or saline before training. In Experiment 4, rats received nor-binaltorphimine (kappa antagonist: 10.0 or 30.0mg/kg, a single injection after completion of PD 15 operant training), spiradoline mesylate (kappa agonist: 1.0 or 5.0mg/kg; at PDs 16-18) or saline (PDs 16-18), before the conditioning. Experiments 5 and 6 assessed possible side effects of opioid drugs in locomotor activity (LA) and conditioned taste aversion (CTA). Ethanol at 7.5 and 10% promoted the highest levels of operant responding. BELs were 12-15mg/dl. In Experiment 3 naltrindole (dose-response effect) and CTOP (the lowest dose) were effective in decreasing operant responding. Nor-binaltorphimine at 10.0mg/kg and spiradoline at 5.0mg/kg also blocked ethanol responding. The effects of opioid drugs on ethanol reinforcement cannot be explained by effects on LA or CTA. Even though particular aspects of each opioid receptor require further testing, a fully functional opioid system seems to be necessary for ethanol reinforcement, during early ontogeny.
[Pubmed: 22789403]
| | 23. |
2012 Jun 26 |
Intranasal administration of aTf protects and repairs the neonatal white matter after a cerebral hypoxic-ischemic event.
Guardia Clausi M, Paez PM, Campagnoni AT, Pasquini LA, Pasquini JM
Glia. 2012 Oct;60(10):1540-54. Epub 2012 Jun 26.
Abstract
Our previous studies showed that the intracerebral injection of apotransferrin (aTf) attenuates white matter damage and accelerates the remyelination process in a neonatal rat model of cerebral hypoxia-ischemia (HI) injury. However, the intracerebral injection of aTf might not be practical for clinical treatments. Therefore, the development of less invasive techniques capable of delivering aTf to the central nervous system would clearly aid in its effective clinical use. In this work, we have determined whether intranasal (iN) administration of human aTf provides neuroprotection to the neonatal mouse brain following a cerebral hypoxic-ischemic event. Apotransferrin was infused into the naris of neonatal mice and the HI insult was induced by right common carotid artery ligation followed by exposure to low oxygen concentration. Our results showed that aTf was successfully delivered into the neonatal HI brain and detected in the olfactory bulb, forebrain and posterior brain 30 min after inhalation. This treatment successfully reduced white matter damage, neuronal loss and astrogliosis in different brain regions and enhanced the proliferation and survival of oligodendroglial progenitor cells (OPCs) in the subventricular zone and corpus callosum (CC). Additionally, using an in vitro hypoxic model, we demonstrated that aTf prevents oligodendrocyte progenitor cell death by promoting their differentiation. In summary, these data suggest that iN administration of aTf has the potential to be used for clinical treatment to protect myelin and to induce remyelination in demyelinating hypoxic-ischemic events in the neonatal brain. © 2012 Wiley Periodicals, Inc.
[Pubmed: 22736466]
| | 24. |
2012 Jun 20 |
Bottom-up effects may not reach the top: the influence of ant-aphid interactions on the spread of soil disturbances through trophic chains.
Lescano MN, Farji-Brener AG, Gianoli E, Carlo TA
Proc. Biol. Sci. 2012 Sep 22;279(1743):3779-87. Epub 2012 Jun 20.
Abstract
Soil disturbances that increase nutrient availability may trigger bottom-up cascading effects along trophic chains. However, the strength and sign of these effects may depend on attributes of the interacting species. Here, we studied the effects of nutrient-rich refuse dumps of the leaf-cutting ant, Acromyrmex lobicornis, on the food chain composed of thistles, aphids, tending ants and aphid natural enemies. Using stable isotopes tracers, we show that the nitrogen accumulated in refuse dumps propagates upward through the studied food chain. Thistles growing on refuse dumps had greater biomass and higher aphid density than those growing in adjacent soil. These modifications did not affect the structure of the tending ant assemblage, but were associated with increased ant activity. In contrast to the expectations under the typical bottom-up cascade effect, the increase in aphid abundance did not positively impact on aphid natural enemies. This pattern may be explained by both an increased activity of tending ants, which defend aphids against their natural enemies, and the low capacity of aphid natural enemies to show numerical or functional responses to increased aphid density. Our results illustrate how biotic interactions and the response capacity of top predators could disrupt bottom-up cascades triggered by disturbances that increase resource availability.
[Pubmed: 22719029]
| | 25. |
2012 Jul |
Genetic risk
ten Kate
J Community Genet 2012 Jul;3(3):159-166.
Abstract
In this paper I will review different aspects of genetic risk in the context of preconception care. I restrict myself to the knowledge of risk which is relevant for care and/or enables reproductive choice. The paper deals with chromosomes, genes and the genetic classification of diseases, and it explains why Mendelian disorders frequently do not show the expected pattern of occurrence in families. Factors that amplify genetic risk are also discussed. Of the two methods of genetic risk assessment—history taking and genetic screening—the former method is examined to some extent, and the consequences of an inadequate family history are illustrated in a case report. The paper ends with a review of the sparse literature available on the frequency of a positive family history and an outline of the challenges and rewards faced by professionals when confronted with a positive history.
[Pubmed: 22893513]
| | 26. |
2012 Jun 01 |
Tumor-specific MAGE proteins as regulators of p53 function.
Ladelfa MF, Peche LY, Toledo MF, Laiseca JE, Schneider C, Monte M
Cancer Lett. 2012 Dec 1;325(1):11-7. Epub 2012 Jun 01.
Abstract
Since its discovery in 1991, the knowledge about the tumor specific melanoma antigen gene (MAGE-I) family has been continuously increasing. Initially, MAGE-I proteins were considered as selective targets for immunotherapy. More recently, emerging data obtained from different cellular mechanisms controlled by MAGE-I proteins suggest a key role in the regulation of important pathways linked to cell proliferation. This is in part due to the ability of some MAGE-I proteins to control the p53 tumor suppressor. In this review, we focus on the mechanisms proposed to explain how MAGE-I proteins affect p53 functions.
[Pubmed: 22664239]
| | 27. |
2012 Jun 12 |
The position of the double bond in monounsaturated free fatty acids is essential for the inhibition of the nicotinic acetylcholine receptor.
Perillo VL, Fernández-Nievas GA, Vallés AS, Barrantes FJ, Antollini SS
Biochim. Biophys. Acta. 2012 Nov;1818(11):2511-20. Epub 2012 Jun 12.
Abstract
Free fatty acids (FFAs) are non-competitive antagonists of the nicotinic acetylcholine receptor (AChR). Their site of action is supposedly located at the lipid-AChR interface. To elucidate the mechanism involved in this antagonism, we studied the effect that FFAs with a single double-bond at different positions (ω6, ω9, ω11 and ω13 cis-18:1) have on different AChR properties. Electrophysiological studies showed that only two FFAs (ω6 and ω9) reduced the duration of the channel open-state. The briefest component of the closed-time distribution remained unaltered, suggesting that ω6 and ω9 behave as allosteric blockers. Fluorescence resonance energy transfer studies indicated that all FFAs locate at the lipid-AChR interface, ω6 being restricted to annular sites and all others occupying non-annular sites. The perturbation of the native membrane order by FFAs was evaluated by DPH (1,6-diphenyl-1,3,5-hexatriene) and Laurdan fluorescence polarization studies, with the greatest decrease observed for ω9 and ω11. AChR conformational changes produced by FFAs present at the lipid bilayer were evaluated by fluorescence quenching studies of pyrene-labeled AChR and also using the AChR conformational-sensitive probe crystal violet. All cis-FFAs produced AChR conformational changes at the transmembrane level, but only ω9, ω11 and ω13 perturbed the resting state. Thus, the position and isomerism of the torsion angle of unsaturated FFAs are probably a key factor in terms of AChR blockage, suggesting that FFAs with a unique cis double bond at a superficial position inside the membrane directly inhibit AChR function by perturbing a potential conserved core structure for AChR gating at that level.
[Pubmed: 22699039]
| | 28. |
2012 Jun 06 |
Evolution of Linear Motifs within the Papillomavirus E7 Oncoprotein.
Chemes LB, Glavina J, Faivovich J, de Prat-Gay G, Sánchez IE
J. Mol. Biol. 2012 Sep 21;422(3):336-46. Epub 2012 Jun 06.
Abstract
Many protein functions can be traced to linear sequence motifs of less than five residues, which are often found within intrinsically disordered domains. In spite of their prevalence, their role in protein evolution is only beginning to be understood. The study of papillomaviruses has provided many insights on the evolution of protein structure and function. We have chosen the papillomavirus E7 oncoprotein as a model system for the evolution of functional linear motifs. The multiple functions of E7 proteins from paradigmatic papillomavirus types can be explained to a large extent in terms of five linear motifs within the intrinsically disordered N-terminal domain and two linear motifs within the globular homodimeric C-terminal domain. We examined the motif inventory of E7 proteins from over 200 known papillomavirus types and found that the motifs reported for paradigmatic papillomavirus types are absent from many uncharacterized E7 proteins. Several motif pairs occur more often than expected, suggesting that linear motifs may evolve and function in a cooperative manner. The E7 linear motifs have appeared or disappeared multiple times during papillomavirus evolution, confirming the evolutionary plasticity of short functional sequences. Four of the motifs appeared several times during papillomavirus evolution, providing direct evidence for convergent evolution. Interestingly, the evolution pattern of a motif is independent of its location in a globular or disordered domain. The correlation between the presence of some motifs and virus host specificity and tissue tropism suggests that linear motifs play a role in the adaptive evolution of papillomaviruses.
[Pubmed: 22683353]
| | 29. |
2012 Aug 15 |
Non-equilibrium conductance through a benzene molecule in the Kondo regime.
Tosi L, Roura-Bas P, Aligia AA
J Phys Condens Matter. 2012 Sep 12;24(36):365301. Epub 2012 Aug 15.
Abstract
Starting from exact eigenstates for a symmetric ring, we derive a low-energy effective generalized Anderson Hamiltonian which contains two spin doublets with opposite momenta and a singlet for the neutral molecule. For benzene, the singlet (doublets) represent the ground state of the neutral (singly charged) molecule. We calculate the non-equilibrium conductance through a benzene molecule, doped with one electron or a hole (i.e. in the Kondo regime), and connected to two conducting leads at different positions. We solve the problem using the Keldysh formalism and the non-crossing approximation. When the leads are connected in the para position (at 180°), the model is equivalent to the ordinary impurity Anderson model and its known properties are recovered. For other positions, there is a partial destructive interference in the co-tunneling processes involving the two doublets and, as a consequence, the Kondo temperature and the height and width of the central peak (for bias voltage V(b) near zero) of the differential conductance G = dI/dV(b) (where I is the current) are reduced. In addition, two peaks at finite V(b) appear. We study the position of these peaks, the temperature dependence of G and the spectral densities. Our formalism can also be applied to carbon nanotube quantum dots with intervalley mixing.
[Pubmed: 22892707]
| | 30. |
2012 Jul 08 |
Role of thymulin on the somatotropic axis in vivo.
Reggiani PC, Martines EV, Camihort GA, Poch B, Goya RG, Cónsole GM
Life Sci. 2012 Sep 4;91(5-6):166-71. Epub 2012 Jul 08.
Abstract
There is clear evidence for the existence of a bi-directional thymus-somatotropic axis and several studies suggest that the thymic peptide thymulin may be involved in this communication. We undertook to assess the impact of serum thymulin immunoneutralization in C57BL/6 mice and that of neonatal thymulin gene therapy (NTGT) in nude mice on body weight (BW) gain and on the histomorphometric profile of the somatotrope population.
[Pubmed: 22781709]
| | 31. |
2012 Jul 04 |
Differential mechanisms of action are involved in chlorpyrifos effects in estrogen-dependent or -independent breast cancer cells exposed to low or high concentrations of the pesticide.
Ventura C, Núñez M, Miret N, Martinel Lamas D, Randi A, Venturino A, Rivera E, Cocca C
Toxicol. Lett. 2012 Sep 3;213(2):184-93. Epub 2012 Jul 04.
Abstract
It has reported that many environmental compounds may display estrogenic actions and these findings led to researchers to associate breast cancer risk with the use of some pesticides. The aim of this work was to investigate the effect of chlorpyrifos (CPF) on cell proliferation and the ERα-dependence of this action employing MCF-7 and MDA-MB-231 breast cancer cell lines. We have also analyzed CPF action on the cell cycle distribution and the cyclins that are implicated in G1-S and intra-S checkpoints. Finally, the action on cell death and ROS production were studied. We demonstrated the ability of CPF 0.05μM to induce cell proliferation through ERα in hormone-dependent breast cancer cells. In contrast, CPF 50μM induces intra-S arrest modifying checkpoints proteins, through a mechanism that may involve changes in redox balance in MCF-7. In MDA-MB-231, we have found that CPF 50μM produces an arrest in G2/M phase which could be related to the capacity of the pesticide for binding to tubulin sites altering microtubules polymerization. Altogether, our results provide new evidences on the action of the pesticide CPF as an environmental breast cancer risk factor due to the effects that causes on the mechanisms that modulate breast cell proliferation.
[Pubmed: 22771950]
| | 32. |
2012 Aug 15 |
Geological Substrates Shape Tree Species and Trait Distributions in African Moist Forests
Fayolle, Engelbrecht, Freycon, Mortier, Swaine, Réjou-Méchain, Doucet, Fauvet, Cornu, Gourlet-Fleury
PLoS One 2012 Aug 15;7(8). published online before print
Abstract
Understanding the factors that shape the distribution of tropical tree species at large scales is a central issue in ecology, conservation and forest management. The aims of this study were to (i) assess the importance of environmental factors relative to historical factors for tree species distributions in the semi-evergreen forests of the northern Congo basin; and to (ii) identify potential mechanisms explaining distribution patterns through a trait-based approach.
[Pubmed: 22905127]
| | 33. |
2012 Aug 15 |
Scale-Dependent Effects of a Heterogeneous Landscape on Genetic Differentiation in the Central American Squirrel Monkey (Saimiri oerstedii)
Blair, Melnick
PLoS One 2012 Aug 15;7(8). published online before print
Abstract
Landscape genetic studies offer a fine-scale understanding of how habitat heterogeneity influences population genetic structure. We examined population genetic structure and conducted a landscape genetic analysis for the endangered Central American Squirrel Monkey (Saimiri oerstedii) that lives in the fragmented, human-modified habitats of the Central Pacific region of Costa Rica. We analyzed non-invasively collected fecal samples from 244 individuals from 14 groups for 16 microsatellite markers. We found two geographically separate genetic clusters in the Central Pacific region with evidence of recent gene flow among them. We also found significant differentiation among groups of S. o. citrinellus using pairwise FST comparisons. These groups are in fragments of secondary forest separated by unsuitable “matrix” habitats such as cattle pasture, commercial African oil palm plantations, and human residential areas. We used an individual-based landscape genetic approach to measure spatial patterns of genetic variance while taking into account landscape heterogeneity. We found that large, commercial oil palm plantations represent moderate barriers to gene flow between populations, but cattle pastures, rivers, and residential areas do not. However, the influence of oil palm plantations on genetic variance was diminished when we restricted analyses to within population pairs, suggesting that their effect is scale-dependent and manifests during longer dispersal events among populations. We show that when landscape genetic methods are applied rigorously and at the right scale, they are sensitive enough to track population processes even in species with long, overlapping generations such as primates. Thus landscape genetic approaches are extremely valuable for the conservation management of a diverse array of endangered species in heterogeneous, human-modified habitats. Our results also stress the importance of explicitly considering the heterogeneity of matrix habitats in landscape genetic studies, instead of assuming that all matrix habitats have a uniform effect on population genetic processes.
[Pubmed: 22905197]
| | 34. |
2012 Aug 15 |
Opportunities for Web-Based Indicators in Environmental Sciences
Malcevschi, Marchini, Savini, Facchinetti
PLoS One 2012 Aug 15;7(8). published online before print
Abstract
This paper proposes a set of web-based indicators for quantifying and ranking the relevance of terms related to key-issues in Ecology and Sustainability Science. Search engines that operate in different contexts (e.g. global, social, scientific) are considered as web information carriers (WICs) and are able to analyse; (i) relevance on different levels: global web, individual/personal sphere, on-line news, and culture/science; (ii) time trends of relevance; (iii) relevance of keywords for environmental governance. For the purposes of this study, several indicators and specific indices (relational indices and dynamic indices) were applied to a test-set of 24 keywords. Outputs consistently show that traditional study topics in environmental sciences such as water and air have remained the most quantitatively relevant keywords, while interest in systemic issues (i.e. ecosystem and landscape) has grown over the last 20 years. Nowadays, the relevance of new concepts such as resilience and ecosystem services is increasing, but the actual ability of these concepts to influence environmental governance needs to be further studied and understood. The proposed approach, which is based on intuitive and easily replicable procedures, can support the decision-making processes related to environmental governance.
[Pubmed: 22905118]
| | 35. |
2012 Aug 15 |
Seropositivity of Lyme Borreliosis and Associated Risk Factors: A Population-Based Study in Children and Adolescents in Germany (KiGGS)
Dehnert, Fingerle, Klier, Talaska, Schlaud, Krause, Wilking, Poggensee
PLoS One 2012 Aug 15;7(8). published online before print
Abstract
Lyme borreliosis (LB) caused by spirochetes of the Borrelia burgdorferi sensu lato complex is the most common tick-borne disease in the northern hemisphere. Data on the distribution and on risk factors in Germany are sketchy.
[Pubmed: 22905101]
| | 36. |
2012 Aug 15 |
A C1q Domain Containing Protein from Scallop Chlamys farreri Serving as Pattern Recognition Receptor with Heat-Aggregated IgG Binding Activity
Wang, Wang, Zhang, Zhou, Siva, Song
PLoS One 2012 Aug 15;7(8). published online before print
Abstract
The C1q domain containing (C1qDC) proteins refer to a family of all proteins that contain the globular C1q (gC1q) domain, and participate in a series of immune responses depending on their gC1q domains to bind a variety of self and non-self binding ligands.
[Pubmed: 22905248]
| | 37. |
2012 Aug 15 |
Laboratory and Clinical Predictors of Disease Progression following Initiation of Combination Therapy in HIV-Infected Adults in Thailand
Duong, Jourdain, Ngo-Giang-Huong, Le Cœur, Kantipong, Buranabanjasatean, Leenasirimakul, Ariyadej, Tansuphasawasdikul, Thongpaen, Lallemant,
PLoS One 2012 Aug 15;7(8). published online before print
Abstract
Data on determinants of long-term disease progression in HIV-infected patients on antiretroviral therapy (ART) are limited in low and middle-income settings.
[Pubmed: 22905264]
| | 38. |
2012 Aug 14 |
Phenotypic Characterization of Peripheral T Cells and Their Dynamics in Scrub Typhus Patients
Cho, Ko, Kim, Kim, Choi, Kim, Kim, Cho
PLoS Negl Trop Dis 2012 Aug 14;6(8). published online before print
Abstract
Scrub typhus, caused by Orientia tsutsugamushi infection, is one of the main causes of febrile illness in the Asia-Pacific region. Although cell-mediated immunity plays an important role in protection, little is known about the phenotypic changes and dynamics of leukocytes in scrub typhus patients.
[Pubmed: 22905277]
| | 39. |
2012 Aug 14 |
Toxocariasis and Epilepsy: Systematic Review and Meta-Analysis
Quattrocchi, Nicoletti, Marin, Bruno, Druet-Cabanac, Preux
PLoS Negl Trop Dis 2012 Aug 14;6(8). published online before print
Abstract
Human toxocariasis is a zoonotic infection caused by the larval stages of Toxocara canis (T. canis) and less frequently Toxocara cati (T. cati). A relationship between toxocariasis and epilepsy has been hypothesized. We conducted a systematic review and a meta-analysis of available data to evaluate the strength of association between epilepsy and Toxocara spp. seropositivity and to propose some guidelines for future surveys.
[Pubmed: 22905274]
| | 40. |
2012 Aug 14 |
Spatial Heterogeneity and Risk Maps of Community Infestation by Triatoma infestans in Rural Northwestern Argentina
Vazquez-Prokopec, Spillmann, Zaidenberg, Gürtler, Kitron
PLoS Negl Trop Dis 2012 Aug 14;6(8). published online before print
Abstract
Fifty years of residual insecticide spraying to control Triatoma infestans in the Gran Chaco region of northern Argentina, Paraguay and Bolivia shows that vertically coordinated interventions aiming at full coverage have limited effects and are unsustainable. We quantified the spatial distribution of T. infestans domestic infestation at the district level, identified environmental factors associated with high infestation and then explored the usefulness of risk maps for the spatial stratification of interventions.
[Pubmed: 22905276]
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