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51.
52.
Jiayue Yan Josué Martínez-de la Puente Laura Gangoso Rafael Gutiérrez-López Ramón Soriguer Jordi Figuerola 《International journal for parasitology》2018,48(3-4):257-264
Pathogen-induced host phenotypic changes are widespread phenomena that can dramatically influence host–vector interactions. Enhanced vector attraction to infected hosts has been reported in a variety of host–pathogen systems, and has given rise to the parasite manipulation hypothesis whereby pathogens may adaptively modify host phenotypes to increase transmission from host to host. However, host phenotypic changes do not always favour the transmission of pathogens, as random host choice, reduced host attractiveness and even host avoidance after infection have also been reported. Thus, the effects of hosts’ parasitic infections on vector feeding behaviour and on the likelihood of parasite transmission remain unclear. Here, we experimentally tested how host infection status and infection intensity with avian Plasmodium affect mosquito feeding patterns in house sparrows (Passer domesticus). In separate experiments, mosquitoes were allowed to bite pairs containing (i) one infected and one uninfected bird and (ii) two infected birds, one of which treated with the antimalarial drug, primaquine. We found that mosquitoes fed randomly when exposed to both infected and uninfected birds. However, when mosquitoes were exposed only to infected individuals, they preferred to bite the non-treated birds. These results suggest that the malarial parasite load rather than the infection itself plays a key role in mosquito attraction. Our findings partially support the parasite manipulation hypothesis, which probably operates via a reduction in defensive behaviour, and highlights the importance of considering parasite load in studies on host–vector–pathogen interactions. 相似文献
53.
Marsillach J Ferré N Camps J Rull A Beltran R Joven J 《Molecular and cellular biochemistry》2008,308(1-2):101-109
Chronic liver diseases are accompanied by changes in the biochemical pathways related to the regulation of apoptosis and extra-cellular
matrix deposition. The present study was designed to investigate, using low density arrays, changes in the hepatic gene expression
together with hepatic biochemical and histological alterations in rats that had liver impairment induced by chronic exposure
to CCl4. Further, we examined the possible recovery of genetic and pathological changes following the cessation of the hepatotoxic
injury. Experimental fibrosis was induced in male Wistar rats by CCl4 administration. Animals were subdivided into two groups. One group was given CCl4 and animals were killed at 8 and 12 weeks of treatment. The other group was treated with CCl4 for 6 weeks, the CCl4 was then stopped and, subsequently, subgroups of animals were killed after 1 and 2 weeks of recovery. CCl4 administration over 12 weeks was associated with significant changes in B-cell leukemia/lymphoma 2, procollagen type I α
2, matrix metalloproteinases 3 and 8, tissue inhibitors of metalloproteinases 1, 2, and 3 and the inhibitor of apoptosis 4
gene expressions. Recovery after CCl4 cessation was associated with changes in procollagen type I α 2, matrix metalloproteinase 7, tissue inhibitors of metalloproteinases
1 and 2, inhibitor of apoptosis 4, and survivin gene expressions. This study shows an association between changes in the expression
of several genes regulating hepatic cell apoptosis, the fibrosis process, and the recovery of the hepatic function after removal
of the toxic injury. 相似文献
54.
Domènech J Bofill R Tinti A Torreggiani A Atrian S Capdevila M 《Biochimica et biophysica acta》2008,1784(4):693-704
Tetrahymena pyriformis MT1 (TpyMT1) is a model among ciliate metallothioneins (MTs). Here, we report on the analytic (ICP-AES, GC-FPD), spectroscopic (CD, UV-Vis, Raman) and spectrometric (ESI-MS) characterization of its recombinant Cd(II)-, Zn(II)- and Cu(I)-complexes, and of those formed during in vitro Zn/Cd and Zn/Cu replacement. In the presence of Cd(II), TpyMT1 renders a major Cd 11-TpyMT1 species, which is also the final step reached in the in vitro Zn/Cd exchange process in Zn 11-TpyMT1. Spectroscopic data supports a different folding of the isostoichiometric Cd 11- and Zn 11-TpyMT1 complexes. Unexpectedly, TpyMT1 biosynthesis in Zn(II)-rich cultures was sensitive to the aeration degree, so that high oxygenation rendered undermetalated, partially-oxidized, complexes (Zn9-TpyMT1). Biosynthesis in Cu(I)-rich media rendered extremely heterogeneous mixtures of CuxZny-species (x+y=8-20), where the higher the aeration, the higher the Zn(II) content. The complexity of these samples was reproduced during the Zn/Cu replacement, as the number of generated species increased gradually with the addition of copper to Zn(11)-TpyMT1. According to our results, a clear preference of TpyMT1 for Cd(II) binding, rather than for Zn(II), and especially Cu(I) can be postulated. This character is totally consistent with the induction pattern of the TpyMT1 gene and the postulated role of TpyMT1 in Cd-detoxification. 相似文献
55.
Emili Saló Ana Maria Muñoz-Mármol José Ramon Bayascas-Ramirez Jordi Garcia-Fernàndez Agusti Miralles Andreu Casali Montserrat Corominas Jaume Baguñá 《Hydrobiologia》1995,305(1-3):269-275
To identify potential pattern control and cell determination and/or differentiation genes in the freshwater planarian Dugesial (G.) tigrina, we searched for homeobox genes of different types in the genome of this primitive metazoan. We applied two basic approaches: 1) Screening the cDNA library with degenerate oligonucleotides corresponding to the most conserved amino acid sequence from helix-3 of the homeodomain of each family; and 2) PCR amplification of genomic DNA or cDNA, using two sets of degenerated oligonucleotides corresponding to helices 1 and 3 of the homeodomain or two specific domains of the POU family. Using the first strategy we have identified and characterized two tissue-specific cell determination and/or differentiation NK-type homeobox genes. Using the second strategy we have identified several homeobox genes that belong to the HOM/Hox, paired (prd) or POU families. 相似文献
56.
Gee AO Baker BM Silverstein AM Montero G Esterhai JL Mauck RL 《Cell and tissue research》2012,347(3):803-813
Electrospun scaffolds hold promise for the regeneration of dense connective tissues, given their nanoscale topographies, provision
of directional cues for infiltrating cells and versatile composition. Synthetic slow-degrading scaffolds provide long-term
mechanical support and nanoscale instructional cues; however, these scaffolds suffer from a poor infiltration rate. Alternatively,
nanofibrous constructs formed from natural biomimetic materials (such as collagen) rapidly infiltrate but provide little mechanical
support. To take advantage of the positive features of these constructs, we have developed a composite scaffold consisting
in both a biomimetic fiber fraction (i.e., Type I collagen nanofibers) together with a traditional synthetic (i.e., poly-[ε-caprolactone],
PCL) fiber fraction. We hypothesize that inclusion of biomimetic elements will improve initial cell adhesion and eventual
scaffold infiltration, whereas the synthetic elements will provide controlled and long-term mechanical support. We have developed
a method of forming and crosslinking collagen nanofibers by using the natural crosslinking agent genipin (GP). Further, we
have formed composites from collagen and PCL and evaluated the long-term performance of these scaffolds when seeded with mesenchymal
stem cells. Our results demonstrate that GP crosslinking is cytocompatible and generates stable nanofibrous type I collagen
constructs. Composites with varying fractions of the biomimetic and synthetic fiber families are formed and retain their collagen
fiber fractions during in vitro culture. However, at the maximum collagen fiber fractions (20%), cell ingress is limited compared
with pure PCL scaffolds. These results provide a new foundation for the development and optimization of biomimetic/synthetic
nanofibrous composites for in vivo tissue engineering. 相似文献
57.
González S Moreno-Delgado D Moreno E Pérez-Capote K Franco R Mallol J Cortés A Casadó V Lluís C Ortiz J Ferré S Canela E McCormick PJ 《PLoS biology》2012,10(6):e1001347
The role of the pineal gland is to translate the rhythmic cycles of night and day encoded by the retina into hormonal signals that are transmitted to the rest of the neuronal system in the form of serotonin and melatonin synthesis and release. Here we describe that the production of both melatonin and serotonin by the pineal gland is regulated by a circadian-related heteromerization of adrenergic and dopamine D4 receptors. Through α1
B-D4 and β1-D4 receptor heteromers dopamine inhibits adrenergic receptor signaling and blocks the synthesis of melatonin induced by adrenergic receptor ligands. This inhibition was not observed at hours of the day when D4 was not expressed. These data provide a new perspective on dopamine function and constitute the first example of a circadian-controlled receptor heteromer. The unanticipated heteromerization between adrenergic and dopamine D4 receptors provides a feedback mechanism for the neuronal hormone system in the form of dopamine to control circadian inputs. 相似文献
58.
Alícia Martinez-Varela Elena Cerro-Gálvez Adrià Auladell Shalabh Sharma Mary Ann Moran Ronald P. Kiene Benjamí Piña Jordi Dachs Maria Vila-Costa 《Environmental microbiology》2021,23(8):4532-4546
Thousands of man-made synthetic chemicals are released to oceans and compose the anthropogenic dissolved organic carbon (ADOC). Little is known about the effects of this chronic pollution on marine microbiome activities. In this study, we measured the pollution level at three sites in the Northeast Subarctic Pacific Ocean (NESAP) and investigated how mixtures of three model families of ADOC at different environmentally relevant concentrations affected naturally occurring marine bacterioplankton communities' structure and metabolic functioning. The offshore northernmost site (North) had the lowest concentrations of hydrocarbons, as well as organophosphate ester plasticizers, contrasting with the two other continental shelf sites, the southern coastal site (South) being the most contaminated. At North, ADOC stimulated bacterial growth and promoted an increase in the contribution of some Gammaproteobacteria groups (e.g. Alteromonadales) to the 16 rRNA pool. These groups are described as fast responders after oil spills. In contrast, minor changes in South microbiome activities were observed. Gene expression profiles at Central showed the coexistence of ADOC degradation and stress-response strategies to cope with ADOC toxicities. These results show that marine microbial communities at three distinct domains in NESAP are influenced by background concentrations of ADOC, expanding previous assessments for polar and temperate waters. 相似文献
59.
Repullés-Albelda A Montero FE Holzer AS Ogawa K Hutson KS Raga JA 《Parasitology international》2008,57(3):405-414
Two new species of teleost blood fluke belonging to the sanguinicolid genus Paradeontacylix are described from the greater amberjack, Seriola dumerili, i.e. Paradeontacylix ibericus n. sp. from the Iberian Peninsula and Paradeontacylix balearicus n. sp. from the Balearic Islands. P. ibericus n. sp. and P. balearicus n. sp. show morphological similarities with Paradeontacylix kampachi and Paradeontacylix grandispinus respectively, which occur in mixed infection in S. dumerili from Japan. Multivariate analysis of morphometrical data provided statistical evidence for the separation of four species. However, component by component analysis did not show statistically significant differences between P. balearicus and P. grandispinus. Molecular data based on rITS2 and mCO1 gene sequences also supported the separation into four species. Morphological and molecular data were used to examine phylogenetic relationships between Paradeontacylix species from S. dumerili and other species in the genus. The results coincided in revealing two main branches with P. kampachi+P. ibericus and (((P. grandispinus+P. balearicus) Paradeontacylix sanguinicoloides) Paradeontacylix godfreyi). Paradeontacylix odhneri, for which little data are available, was located basal in a separate branch. This is the only species of Paradeontacylix which parasitizes a non-carangid host which might probably explain the separation from the other species. Paired similarities between the Japanese and the Mediterranean species, despite the large geographic distance, could be explained by the speciation of parasite geminate lines before host separation by tectonic events. Consequently, geographic and historical isolation support the morphological and genetic differences leading to the evolution of the new species described here. 相似文献
60.