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311.
CC Barros A Haro FJ Russo I Schadock SS Almeida RA Ribeiro EC Vanzela VP Lanzoni FC Barros MR Moraes MA Mori RF Bacurau M Wurtele AC Boschero EM Carneiro M Bader JB Pesquero RC Araujo 《PloS one》2012,7(7):e40573
The Kallikrein-Kinin System (KKS) has been implicated in several aspects of metabolism, including the regulation of glucose homeostasis and adiposity. Kinins and des-Arg-kinins are the major effectors of this system and promote their effects by binding to two different receptors, the kinin B2 and B1 receptors, respectively. To understand the influence of the KKS on the pathophysiology of obesity and type 2 diabetes (T2DM), we generated an animal model deficient for both kinin receptor genes and leptin (obB1B2KO). Six-month-old obB1B2KO mice showed increased blood glucose levels. Isolated islets of the transgenic animals were more responsive to glucose stimulation releasing greater amounts of insulin, mainly in 3-month-old mice, which was corroborated by elevated serum C-peptide concentrations. Furthermore, they presented hepatomegaly, pronounced steatosis, and increased levels of circulating transaminases. This mouse also demonstrated exacerbated gluconeogenesis during the pyruvate challenge test. The hepatic abnormalities were accompanied by changes in the gene expression of factors linked to glucose and lipid metabolisms in the liver. Thus, we conclude that kinin receptors are important for modulation of insulin secretion and for the preservation of normal glucose levels and hepatic functions in obese mice, suggesting a protective role of the KKS regarding complications associated with obesity and T2DM. 相似文献
312.
Figueiró R Gil-Azevedo LH Maia-Herzog M Monteiro RF 《Memórias do Instituto Oswaldo Cruz》2012,107(3):362-369
We describe the abiotic factors affecting the distribution of black flies at a microhabitat scale, rather than at the regional scale usually present in the literature on the Neotropics. Black fly larvae were sampled from the Tocantins River and three tributaries, located in the Brazilian savanna (state of Tocantins, Brazil) during six bi-monthly sampling periods from October 2004-August 2005. At each sampling site, 15 random quadrats (30 x 30 cm) were sampled each period and for each quadrat were determined mean water velocity, predominant substrate type (rocks, riffle litter or riparian vegetation) and depth detrended correspondence analysis (DCA) was used to determine associations with current velocity, whereas correspondence analysis (CA) was used to estimate site specific current velocity associations. Canonical correspondence analysis (CCA) was used to identify general microhabitat associations. The CCA showed that most species had a trend towards riffle litter, except for Simulium nigrimanum associated with rocky substrate and Simulium cuasiexiguum associated with riparian vegetation. The DCA showed a well defined pattern of water velocity associations. The CA revealed that the species showed different speed associations from one site to another, suggesting different competitive pressures resulting in the occurrence of different realized niches. 相似文献
313.
314.
Roman Dial C Dial RJ Saunders R Lang SA Lee B Wimberger P Dinapoli MS Egiazarov AS Gipple SL Maghirang MR Swartley-McArdle DJ Yudkovitz SR Shain DH 《Molecular phylogenetics and evolution》2012,63(3):577-584
North American ice worms are the largest glacially-obligate metazoans, inhabiting coastal, temperate glaciers between southcentral Alaska and Oregon. We have collected ice worm specimens from 10 new populations, completing a broad survey throughout their geographic range. Phylogenetic analyses of 87 individuals using fragments of nuclear 18S rRNA, and mitochondrial 12S rRNA and cyctochrome c oxidase subunit 1 (CO1) identified 18 CO1 haplotypes with divergence values up to ~10%. Phylogeographic interpretations suggest a St. Elias Range, Alaskan ancestry from an aquatic mesenchytraeid oligochaete during the early-Pliocene. A gradual, northward expansion by active dispersal from the central St. Elias clade characterizes a northern clade that is confined to Alaska (with one exception on Vancouver Island, British Columbia), while a distinct southern clade representing worms from British Columbia, Washington and Oregon was likely founded by a passive dispersal event originating from a northern ancestor. The geographic boundary between central and southern clades coincides with an ice worm distribution gap located in southern Alaska, which appears to have restricted active gene flow throughout the species' evolutionary history. 相似文献
315.
Carvalho FA Carneiro FA Martins IC Assunção-Miranda I Faustino AF Pereira RM Bozza PT Castanho MA Mohana-Borges R Da Poian AT Santos NC 《Journal of virology》2012,86(4):2096-2108
Dengue virus (DENV) affects millions of people, causing more than 20,000 deaths annually. No effective treatment for the disease caused by DENV infection is currently available, partially due to the lack of knowledge on the basic aspects of the viral life cycle, including the molecular basis of the interaction between viral components and cellular compartments. Here, we characterized the properties of the interaction between the DENV capsid (C) protein and hepatic lipid droplets (LDs), which was recently shown to be essential for the virus replication cycle. Zeta potential analysis revealed a negative surface charge of LDs, with an average surface charge of -19 mV. The titration of LDs with C protein led to an increase of the surface charge, which reached a plateau at +13.7 mV, suggesting that the viral protein-LD interaction exposes the protein cationic surface to the aqueous environment. Atomic force microscopy (AFM)-based force spectroscopy measurements were performed by using C protein-functionalized AFM tips. The C protein-LD interaction was found to be strong, with a single (un)binding force of 33.6 pN. This binding was dependent on high intracellular concentrations of potassium ions but not sodium. The inhibition of Na(+)/K(+)-ATPase in DENV-infected cells resulted in the dissociation of C protein from LDs and a 50-fold inhibition of infectious virus production but not of RNA replication, indicating a biological relevance for the potassium-dependent interaction. Limited proteolysis of the LD surface impaired the C protein-LD interaction, and force measurements in the presence of specific antibodies indicated that perilipin 3 (TIP47) is the major DENV C protein ligand on the surface of LDs. 相似文献
316.
de Siqueira RJ Freire WB Vasconcelos-Silva AA Fonseca-Magalhães PA Lima FJ Brito TS Mourão LT Ribeiro RA Lahlou S Magalhães PJ 《Canadian journal of physiology and pharmacology》2012,90(1):23-35
The present study deals with the pharmacological effects of the sesquiterpene alcohol (-)-α-bisabolol on various smooth-muscle preparations from rats. Under resting tonus, (-)-α-bisabolol (30-300?μmol/L) relaxed duodenal strips, whereas it showed biphasic effects in other preparations, contracting endothelium-intact aortic rings and urinary bladder strips, and relaxing these tissues at higher concentrations (600-1000?μmol/L). In preparations precontracted either electromechanically (by 60?mmol/L K(+)) or pharmacomechanically (by phenylephrine or carbachol), (-)-α-bisabolol showed only relaxing properties. The pharmacological potency of (-)-α-bisabolol was variable, being higher in mesenteric vessels, whereas it exerted relaxing activity with a lesser potency on tracheal or colonic tissues. In tissues possessing spontaneous activity, (-)-α-bisabolol completely decreased spontaneous contractions in duodenum, whereas it increased their amplitude in urinary bladder tissue. Administered in vivo, (-)-α-bisabolol attenuated the increased responses of carbachol in tracheal rings of ovalbumin-sensitized rats challenged with ovalbumin, but was without effect in the decreased responsiveness of urinary bladder strips in mice treated with ifosfamide. In summary, (-)-α-bisabolol is biologically active in smooth muscle. In some tissues, (-)-α-bisabolol preferentially relaxed contractions induced electromechanically, especially in tracheal smooth muscle. The findings from tracheal rings reveal that (-)-α-bisabolol may be an inhibitor of voltage-dependent Ca(2+) channels. 相似文献
317.
Valencia FF Paulucci AA Quaggio RB Da Silva AC Farah CS Reinach FC 《The Journal of biological chemistry》2003,278(13):11007-11014
Calcium binding to chicken recombinant skeletal muscle TnC (TnC) and its mutants containing tryptophan (F29W), 5-hydroxytryptophan (F29HW), or 7-azatryptophan (F29ZW) at position 29 was measured by flow dialysis and by fluorescence. Comparative analysis of the results allowed us to determine the influence of each amino acid on the calcium binding properties of the N-terminal regulatory domain of the protein. Compared with TnC, the Ca(2+) affinity of N-terminal sites was: 1) increased 6-fold in F29W, 2) increased 3-fold in F29ZW, and 3) decreased slightly in F29HW. The Ca(2+) titration of F29ZW monitored by fluorescence displayed a bimodal curve related to sequential Ca(2+) binding to the two N-terminal Ca(2+) binding sites. Single and double mutants of TnC, F29W, F29HW, and F29ZW were constructed by replacing aspartate by alanine at position 30 (site I) or 66 (site II) or both. Ca(2+) binding data showed that the Asp --> Ala mutation at position 30 impairs calcium binding to site I only, whereas the Asp --> Ala mutation at position 66 impairs calcium binding to both sites I and II. Furthermore, the Asp --> Ala mutation at position 30 eliminates the differences in Ca(2+) affinity observed for replacement of Phe at position 29 by Trp, 5-hydroxytryptophan, or 7-azatryptophan. We conclude that position 29 influences the affinity of site I and that Ca(2+) binding to site I is dependent on the previous binding of metal to site II. 相似文献
318.
319.
Mendonça RZ de Oliveira EC Pereira CA Lebrun I 《Bioprocess and biosystems engineering》2007,30(3):157-164
In this study, we have described the biological activity of various hydrolysates and its effect on cell growth, growth rate
and doubling time. A potent cell culture enhancer factor was observed in the yeastolate hydrolysates, mainly in the protein
fractions with low molecular weight. In this case, a growth enhancer of 60.66% was obtained. Despite a lower efficiency of
crude lactalbumin hydrolysates (14%), when lactalbumin and yeastolate were added together to the culture, the cell yields
were of 102%, showing a synergic effect. Nevertheless, sub fraction from LMW, of lactalbumin, obtained by Sephadex G-10 gel
filtration chromatography showed a higher positive effect (23.3%) than low molecular weight fraction of lactalbumin without
this chromatography step (11.3%). It is suggested that low molecular weight lactalbumin could have some inhibitory protein.
On the other hand, NZCase low molecular weight showed a positive effect of 29.33%, while its sub fractions showed a negative
effect of 5.5%. With these data we can suggest that these hydrolysates could be an important element to design new media,
serum free, being helpful in protein recombinant production. 相似文献
320.
Taiana Haag Anelisie S. Santos Carlos De Angelo Ana Carolina Srbek-Araujo Dênis A. Sana Ronaldo G. Morato Francisco M. Salzano Eduardo Eizirik 《Genetica》2009,136(3):505-512
The elusive nature and endangered status of most carnivore species imply that efficient approaches for their non-invasive
sampling are required to allow for genetic and ecological studies. Faecal samples are a major potential source of information,
and reliable approaches are needed to foster their application in this field, particularly in areas where few studies have
been conducted. A major obstacle to the reliable use of faecal samples is their uncertain species-level identification in
the field, an issue that can be addressed with DNA-based assays. In this study we describe a sequence-based approach that
efficiently distinguishes jaguar versus puma scats, and that presents several desirable properties: (1) considerably high
amplification and sequencing rates; (2) multiple diagnostic sites reliably differentiating the two focal species; (3) high
information content that allows for future application in other carnivores; (4) no evidence of amplification of prey DNA;
and (5) no evidence of amplification of a nuclear mitochondrial DNA insertion known to occur in the jaguar. We demonstrate
the reliability and usefulness of this approach by evaluating 55 field-collected samples from four locations in the highly
fragmented Atlantic Forest biome of Brazil and Argentina, and document the presence of one or both of these endangered felids
in each of these areas. 相似文献