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131.
Environmental enrichment has been widely used to improve conditions for nonhuman animals in captivity. However, there is no consensus about the best way to evaluate the success of enrichments. This study evaluated whether the proportion of time spent interacting with enrichments indicated the proportion of overall behavioral changes. Six environmental enrichments were introduced in succession to 16 captive macaws, and interaction of the animals with them as well as the behaviors of the group were recorded before and during the enrichments. All of the enrichments affected the proportions of time spent in different behaviors. Macaws interacted more with certain items (hibiscus and food tree) than with others (a toy or swings and stairs), but introduction of the enrichments that invoked the least interaction caused as many behavioral changes as those that invoked the most. Moreover, feeding behavior was only affected by the enrichment that invoked the least interaction, a change not detected by a general analysis of enrichment effects. In conclusion, little interaction with enrichment does not mean little change in behavior, and the effects of enrichments are more complex than previously considered.  相似文献   
132.
Inflammatory bowel diseases (IBD) is the result of dysregulation of mucosal innate and adaptive immune responses. Factors such as genetic, microbial and environmental are involved in the development of these disorders. Accordingly, animal models that mimic human diseases are tools for the understanding the immunological processes of the IBD as well as to evaluate new therapeutic strategies. Crotoxin (CTX) is the main component of Crotalus durissus terrificus snake venom and has an immunomodulatory effect. Thus, we aimed to evaluate the modulatory effect of CTX in a murine model of colitis induced by 2,4,6- trinitrobenzene sulfonic acid (TNBS). The CTX was administered intraperitoneally 18 hours after the TNBS intrarectal instillation in BALB/c mice. The CTX administration resulted in decreased weight loss, disease activity index (DAI), macroscopic tissue damage, histopathological score and myeloperoxidase (MPO) activity analyzed after 4 days of acute TNBS colitis. Furthermore, the levels of TNF-α, IL-1β and IL-6 were lower in colon tissue homogenates of TNBS-mice that received the CTX when compared with untreated TNBS mice. The analysis of distinct cell populations obtained from the intestinal lamina propria showed that CTX reduced the number of group 3 innate lymphoid cells (ILC3) and Th17 population; CTX decreased IL-17 secretion but did not alter the frequency of CD4+Tbet+ T cells induced by TNBS instillation in mice. In contrast, increased CD4+FoxP3+ cell population as well as secretion of TGF-β, prostaglandin E2 (PGE2) and lipoxin A4 (LXA4) was observed in TNBS-colitis mice treated with CTX compared with untreated TNBS-colitis mice. In conclusion, the CTX is able to modulate the intestinal acute inflammatory response induced by TNBS, resulting in the improvement of clinical status of the mice. This effect of CTX is complex and involves the suppression of the pro-inflammatory environment elicited by intrarectal instillation of TNBS due to the induction of a local anti-inflammatory profile in mice.  相似文献   
133.
We studied the demography and nesting ecology of two populations of Iguana iguana that face heavy exploitation and habitat modification in the Momposina Depression, Colombia. Lineal transect data was analyzed using the Fourier model to provide estimates of social group densities, which was found to differ both within and among populations (1.05-6.0 groups/ha). Mean group size and overall iguana density estimates varied between populations as well (1.5-13.7 iguanas/ha). The density estimates were far lower than those reported from more protected areas in Panama and Venezuela. Iguana densities were consistently higher in sites located along rivers (2.5 iguanas/group) than in sites along the margin of marshes, probably due to vegetational differences (1.5 iguanas/group). There was no correlation between density estimates and estimates of relative abundance (number of iguanas seen/hour/person) due to differing detectabilities of iguana groups among sites. The adult sex ratio (1:2.5 males:females) agreed well with other reports in the literature based upon observation of adult social groups, and probably results from the polygynous mating system in this species rather than a real demographic skew. Nesting in this population occurs from the end of January through March and hatching occurs between April and May. We monitored 34 nests, which suffered little vertebrate predation, perhaps due to the lack of a complete vertebrate fauna in this densely inhabited area, but nests suffered from inundation, cattle trampling, and infestation by phorid fly larvae. Clutch sizes in these populations were lower than all other published reports except for the iguana population on the highly xeric island of Cura?ao, implying that adult females in our area are unusually small. We argue that this is more likely the result of the exploitation of these populations rather than an adaptive response to environmentally extreme conditions.  相似文献   
134.
Gymnotiformes are an important component of the Neotropical ichthyofauna and they are known for their ability to generate and detect electrical discharges. Phylogenetic relationships of Gymnotiformes are still not well understood. However, the monophyly of the superfamily Rhamphichthyoidea is well accepted, despite the position of tribe Steatogenini (Steatogenys, Hypopygus and Stegostenopos) within this superfamily is unclear. The genus Steatogenys includes three species that, together with Hypopygus and Stegostenopos, form tribe Steatogenini. Cytogenetic information is currently only available for Hypopygus lepturus. Here, we describe the karyotypes of Steatogenys elegans from four localities and S. duidae from two localities. S. elegans was found to have 2n = 50, ZZ/ZW (12m-sm/38st-a), while S. duidae had 2n = 50 (50m-sm). In S. elegans, constitutive heterochromatin (CH) was observed in the centromeric regions of all chromosomes, in the interstitial region of 1q, and in two blocks of Wq. In S. duidae, CH was observed in the centromeric and pericentromeric regions of all chromosomes, and in the interstitial regions of 2q, 3q, 5q, and 7q. Nucleolar organizer regions (NORs) were identified in the distal regions of one chromosome pair in each species. The CMA3 fluorochrome (specific to G-C rich regions) coincided with the NORs in both species, and with the HC of S. elegans except on chromosome pair 5 and the W. The DAPI fluorochrome (specific to A-T rich regions) coincided with the CH of both species, and was very intense for chromosome pair 5 and the W of S. elegans. Our observations suggest that the ZZ/ZW system observed in S. elegans likely evolved through CH addition followed by a paracentric inversion. The chromosomal data described herein are consistent with the phylogenetic hypothesis that tribe Steatogenini should be positioned within family Ramphychthyidae.  相似文献   
135.
The prevalence of Mycobacterium bovis and other mycobacterial species in livestock specimens and milk was evaluated. An emphasis was placed upon the distribution of these organisms in milk that is readily available to the public that was either untreated, pasteurized, or treated using ultra high temperature. Twenty-two pathologic specimens from livestock (bovine, swine and bubaline) in five Brazilian states and 128 bovine milk samples from retail markets in the State of S o Paulo were examined for mycobacteria. Identification was made by classical biochemical tests, thin layer chromatography of mycolic acids and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis. Mycobacteria were isolated from 15 (68.2%) caseous lesions and from 23 (18%) milk samples. Eleven isolates were identified as M. bovis, and the remaining 27 nontuberculous mycobacterial isolates were represented by five species and six unidentified rapidly growing mycobacterial strains. The data demonstrate that animal products in Brazil are frequent reservoirs of mycobacteria and may pose a risk to the public.  相似文献   
136.
Praziquantel has been used to treat schistosome infections since 1979 and currently is the only chemotherapeutic agent in production for this purpose, raising concerns about the potential for the emergence of drug resistance. In practice, 10-20% of infected patients will continue to excrete eggs after treatment. It is not understood to what degree this represents selection of a resistant population or incomplete elimination due to the presence of immature worms at the time of treatment. We used a population genetics approach to test whether or not persistent Schistosomamansoni parasites were drawn from the same population as susceptible parasites. In this study, stool samples were collected from 96% of individuals in two small Brazilian communities (populations 482 and 367) and examined for S.mansoni eggs. The combined prevalence of S.mansoni infections in the villages was 41%. Total egg DNA was extracted from each sample and was genotyped at 15 microsatellite markers. Day-to-day variation of the infrapopulation from an individual human host was low (median differentiation using Jost’s D = 0.010), so that a single stool was representative of the genotypes present in stool eggs, at least in the short term. Average pairwise analysis of D among all pre-treatment infrapopulations suggested moderate differentiation (mean D = 0.082 and 0.122 for the two villages), whereas the pre-treatment component population differentiation between the two communities was 0.047. The differentiation of the component population remaining after treatment from the fully susceptible component population was low (mean D = 0.007 and 0.020 for the two villages), suggesting that the persistent parasites were not selected by praziquantel treatment. We will continue to follow these communities for evidence of selection or changes in population structure.  相似文献   
137.
In this study, the effect of cadmium (Cd) on cell viability and its accumulation in Bradyrhizobium spp. (peanut microsymbionts) as well as the role of glutathione (GSH) in the tolerance to this metal were investigated. A reference strain recommended as peanut inoculant (Bradyrhizobium sp. SEMIA6144) grew up to 10 μM Cd meanwhile a GSH-deficient mutant strain (Bradyrhizobium sp. SEMIA6144-S7Z) was unable to grow at this concentration. Two native peanut isolates obtained from Córdoba soils (Bradyrhizobium sp. NLH25 and Bradyrhizobium sp. NOD31) tolerated up to 30 μM Cd. The analysis of Cd content showed that Bradyrhizobium sp. SEMIA6144 accumulated a high amount of this metal, but a considerable inhibition of growth was observed compared to tolerant strains at 10 μM Cd. At this concentration, the intracellular GSH content of all the Bradyrhizobium sp. strains was not modified in comparison to control conditions. However, at 30 μM Cd, the intracellular GSH content significantly increased in Bradyrhizobium sp. strains NLH25 and NOD31. Thus, the distinct response of each Bradyrhizobium sp. strain to Cd reveals that, even in closely related lineages, there are strain-specific variations influencing the levels of tolerance to this metal. Indeed, the native peanut isolates tolerated higher Cd concentration than the reference strain, possibly due to an increase in GSH levels which could act as a detoxifying agent.  相似文献   
138.
A case is presented of an 84 year-old woman who was admitted to the Emergency Department due to an episode of non-calculous acute pancreatitis. In the aetiological study, the presence of a splenic lymphoma was documented, which had a compressive effect on the pancreas. After resolving the symptoms, she was scheduled for a splenectomy with a good technical result. At six months after admission the patient was in an excellent clinical and functional condition. This case highlights the unusual clinical presentation of this haematological disease, and the need to evaluate all the available therapeutic options in selected elderly patients.  相似文献   
139.
140.
After isolating NT‐S100A8 from pancreatic cancer (PC) tissue of diabetic patients, we verified whether this peptide alters PC cell growth and invasion and/or insulin release and [Ca2+]i oscillations of insulin secreting cells and/or insulin signaling. BxPC3, Capan1, MiaPaCa2, Panc1 (PC cell lines) cell growth, and invasion were assessed in the absence or presence of 50, 200, and 500 nM NT‐S100A8. In NT‐S100A8 stimulated β‐TC6 (insulinoma cell line) culture medium, insulin and [Ca2+] were measured at 2, 3, 5, 10, 15, 30, and 60 min, and [Ca2+]i oscillations were monitored (epifluorescence) for 3 min. Five hundred nanomolars NT‐S100A8 stimulated BxPC3 cell growth only and dose dependently reduced MiaPaCa2 and Panc1 invasion. Five hundred nanomolars NT‐S100A8 induced a rapid insulin release and enhanced β‐TC6 [Ca2+]i oscillations after both one (F = 6.05, P < 0.01) and 2 min (F = 7.42, P < 0.01). In the presence of NT‐S100A8, [Ca2+] in β‐TC6 culture medium significantly decreased with respect to control cells (F = 6.3, P < 0.01). NT‐S100A8 did not counteract insulin induced phosphorylation of the insulin receptor, Akt and IκB‐α, but it independently activated Akt and NF‐κB signaling in PC cells. In conclusion, NT‐S100A8 exerts a mild effect on PC cell growth, while it reduces PC cell invasion, possibly by Akt and NF‐κB signaling, NT‐S100A8 enhances [Ca2+]i oscillations and insulin release, probably by inducing Ca2+ influx from the extracellular space, but it does not interfere with insulin signaling. J. Cell. Physiol. 226: 456–468, 2011. © 2010 Wiley‐Liss, Inc.  相似文献   
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