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951.
Wenwen Shen Mariana Sa e Silva Tareq Jaber Olga Vitvitskaia Sumin Li Gail Henderson Clinton Jones 《Journal of virology》2009,83(18):9131-9139
952.
S.C. Bourguignon H.C. Castro C.R. Alves I.L. Gama W.S. Seguins 《Experimental parasitology》2009,122(2):91-96
Chagas disease is an endemic parasitic infection caused by Trypanosomacruzi that affects 18-20 million people in Central and South America. Recently we described the Epoxy-α-Lap, an oxyran derivative of α-lapachone, which presents a low toxicity profile and a high inhibitory activity against T.cruzi epimastigotes forms, the non-infective form of this parasite. In this work we described the trypanocidal effects of Epoxy-α-Lap on extracellular (trypomastigote) and intracellular (amastigote) infective forms of two T. cruzi strains (Y and Colombian) known by their different infective profile. Our results showed that Epoxy-α-Lap is lethal to trypomastigote Y and Colombian strains (97% and 84%, respectively). Interestingly, Epoxy-α-Lap also showed a trypanocidal effect in human macrophage infected with T. cruzi Y (85.6%) and Colombian (71.9%) strains amastigote forms. Similar effects were observed on T. cruzi amastigote infected Vero cells (96.4% and 95.0%, respectively). Our results pointed Epoxy-α-Lap as a potential candidate for Chagas disease chemotherapy since it presents trypanocidal activity on all T. cruzi forms with low) toxicity profile. 相似文献
953.
During the last decades wild rabbit (Oryctolagus cuniculus) populations have been progressively declining in the Iberian Peninsula as a result of several factors, namely habitat deterioration.
Hence, habitat management has become one of the most commonly used management techniques to restore wild rabbit populations.
To test the efficacy of some of these measures (creation of pastures, opening firebreaks) in rabbit populations, two managed
(M1 and M2) and two control areas (C1 and C2) were selected in the Portuguese Southwest (SW) Coast. In each study area, the
influence of habitat management was tested assessing temporal changes in rabbit abundance obtained from pellet counts and
in rabbits’ diet through microhistological analysis of fecal pellets. Rabbit densities were higher in managed than in control
areas (mean annual values: M1–1.08 pellets/m2; M2–1.60 pellets/m2; C1–0.69 pellets/m2; C2–0.40 pellets/m2). In general, Gramineae was the most consumed plant group throughout the year and in all study areas. In control areas, consumption
of alternative species with low nutritive value (e.g., Cistus ladanifer) was observed, especially in summer. Our data suggest a positive influence of habitat management on rabbit populations since
in managed areas individuals presented an overall higher abundance and a more nutritive diet. In addition, there was no evidence
that sown species were consumed in detriment to naturally occurring grasses, suggesting that in Mediterranean semi-arid regions
clearing vegetation inside the scrubland might be sufficient to improve habitat conditions for rabbits. 相似文献
954.
Katia C. S. Figueiredo Helen C. Ferraz Cristiano P. Borges Tito L. M. Alves 《The protein journal》2009,28(5):224-232
The structural stability of metmyoglobin in organic solvents and cosolvents was investigated aiming the choice of a suitable
medium to perform its dissolution with maintenance of the native folding. The spectroscopic behavior of metmyoglobin solution
in UV–Visible and circular dichroism was used to evaluate the solubility and the secondary structure. The results were dependable
of the chemical structure of the organic compounds, their polarity and content, in the case of cosolvents. Protic solvents
showed better ability than the aprotic ones for the biomolecule dissolution, since they are able to establish hydrogen bonds.
Solvents with high polarity usually damage the secondary structure of the protein. Myoglobin was dissolved in pure methanol,
ethylene glycol and glycerol. The secondary structure was retained in some extent. The controlled addition of sodium dodecyl
sulfate to myoglobin aqueous solution changed the surface moiety of the protein. The complex was extracted to hexane with
efficiency of 77%. 相似文献
955.
Fabrícia Gimenes Mariana Aprígio Assis Adriana Fiorini Vânia Aparecida Mareze Nadia Monesi Maria Aparecida Fernandez 《Molecular genetics and genomics : MGG》2009,281(5):539-549
Bent DNA sites promote the curvature of DNA in both eukaryotic and prokaryotic chromosomes. Here, we investigate the localization
and structure of intrinsically bent DNA sites in the extensively characterized Drosophila melanogaster third chromosome DAFC-66D segment (Drosophila amplicon
in the follicle cells). This region contains the amplification control element ACE3, which is a replication enhancer that acts in cis to activate the major replication origin ori-β. Through both electrophoretic and in silico analysis, we have identified three major bent DNA sites in DAFC-66D. The bent DNA site (b1) is localized in the ACE3 element, whereas the other two bent DNA sites (b2 and b3) are localized in the ori-β region. Four additional bent DNA sites were identified in the intron of the S18 gene and near the TATA box of the S15, S19, and S16 genes. The identification of DNA bent sites in genomic regions previously characterized as functionally relevant for DNA
amplification further supports a function for DNA bent sites in DNA replication in eukaryotes.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
956.
Overgrowth of a mouse model of Simpson– Golabi–Behmel syndrome is partly mediated by Indian Hedgehog 下载免费PDF全文
Loss‐of‐function mutations of Glypican 3 (Gpc3) cause the Simpson–Golabi–Behmel overgrowth syndrome (SGBS), and developmental overgrowth is observed in Gpc3‐null mice, a mouse model for SGBS. We recently reported that GPC3 inhibits Hedgehog (Hh) signalling by inducing its endocytosis and degradation. Here, we show that the developmental overgrowth observed in Gpc3‐null mice is, at least in part, a consequence of the hyperactivation of the Hh pathway. We bred Gpc3‐null mice with mice that are Hh signalling‐deficient owing to the lack of Indian Hh (Ihh), one of the three mammalian Hhs. We found that the Gpc3‐null mice showed a 29.9% overgrowth in an Ihh wild‐type background, whereas an Ihh‐null background partly rescues the overgrowth caused by the lack of Gpc3 as the double mutants were 19.8% bigger than the Ihh‐null mice. Consistent with the role of GPC3 in Hh endocytosis and degradation, the Gpc3‐null mice show increased levels of Ihh protein and signalling, but similar levels of Ihh messenger RNA. 相似文献
957.
958.
Petra Korać Radmila Ajduković Mirjana Mariana Kardum Paro Branimir Jakšić Mara Dominis 《Journal of molecular histology》2009,40(1):81-86
This paper shows a protocol for the detection of ZAP-70 expression in B-CLL (B cell chronic lymphocytic leukemia) tumor cells
by common immunohistochemical methods. The study was conducted on bone marrow trephine biopsies from 62 B-CLL patients at
the time of diagnosis. Immunohistochemical reactions based on peroxidase and alkaline phosphatase reactions were used, as
well as double immunofluorescent labeling for ZAP-70 detection as an indirect marker of mutated and unmutated CLL. Clinical
relevance of the ZAP-70 expression detection method was assessed using χ
2 test between ZAP-70 positivity data and other known prognostic factors, i.e., clinical and cytogenetics data. ZAP-70 was
detected in 13 out of 62 patients. Statistically significant results were obtained for ZAP-70 positive cases and known indicators
of worse prognosis. Immunohistochemical analysis supported by double immunfluorescent labeling, as shown here, is an easy
and reliable technique for the detection of ZAP-70 expression in B-CLL tumor cells applicable in every hematopathology laboratory. 相似文献
959.
Anti-predator behaviour often represents a trade-off between the benefits of reducing predation risk and the drawbacks of
limiting access to resources (e.g. food availability, mating and nesting sites). The effectiveness of avoidance behaviour
relies on the ability to detect predator cues, which may provide reliable information on predation risk. Using controlled
laboratory experiments, we studied the relative importance of visual and chemical cues in the triggering of anti-predator
responses in Galaxias maculatus, where Oncorhyncus mykiss was used as the predator. Metabolic cost was also estimated, measured as oxygen consumption. Exposure to different types
of predator cue induced diverse behavioural responses in G. maculatus. Detection of the exotic predator, using both visual and chemical stimuli, resulted in reduced G. maculatus swimming activity and changes in respiratory rate. 相似文献
960.
Andrew P. A. Oxley Mariana P. Lanfranconi Dieco Würdemann Stephan Ott Stefan Schreiber Terry J. McGenity Kenneth N. Timmis Balbina Nogales 《Environmental microbiology》2010,12(9):2398-2410
The human gastrointestinal tract microbiota, despite its key roles in health and disease, remains a diverse, variable and poorly understood entity. Current surveys reveal a multitude of undefined bacterial taxa and a low diversity of methanogenic archaea. In an analysis of the microbiota in colonic mucosal biopsies from patients with inflammatory bowel disease we found 16S rDNA sequences representing a phylogenetically rich diversity of halophilic archaea from the Halobacteriaceae (haloarchaea), including novel phylotypes. As the human colon is not considered a salty environment and haloarchaea are described as extreme halophiles, we evaluated and further discarded the possibility that these sequences originated from pre‐colonoscopy saline lavage solutions. Furthermore, aerobic enrichment cultures prepared from a patient biopsy at low salinity (2.5% NaCl) yielded haloarchaeal sequence types. Microscopic observation after fluorescence in situ hybridization provided evidence of the presence of viable archaeal cells in these cultures. These results prove the survival of haloarchaea in the digestive system and suggest that they may be members of the mucosal microbiota, even if present in low numbers in comparison with methanogenic archaea. Investigation of a potential physiological basis of this association may lead to new insights into gastrointestinal health and disease. 相似文献