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Lopes LP Pimpão DM Takemoto RM Malta JC Varella AM 《Journal of invertebrate pathology》2011,106(3):357-359
Larvae of Hysterothylacium use various invertebrates as intermediate hosts. Definite hosts include fish, birds, reptiles or marine mammals. This study describes the occurrence of Hysterothylacium (Nematoda, Anisakidae) larvae parasitizing the pericardic cavity of Diplodon suavidicus (Unioniformes, Hyriidae) specimens collected in the Amazon basin, Brazil. This is the first record of this nematode parasitizing freshwater bivalves in South America. The high prevalence, medium intensity and medium abundance suggest that D. suavidicus acts as intermediate host for Hysterothylacium species in that environment. 相似文献
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Bruno Caetano Trindade Carlos Artério Sorgi Larissa Deadame de Figueiredo Nicolete Tathiane Maistro Malta Mariana Tomazini Pinto Osvaldo Massaiti Takayanagui Dimas Tadeu Covas Olindo Assis Martins Filho Simone Kashima Lúcia Helena Faccioli 《PloS one》2012,7(12)
Leukotrienes (LTs) are lipid mediators involved in several inflammatory disorders. We investigated the LT pathway in human T-lymphotropic virus type 1 (HTLV-1) infection by evaluating LT levels in HTLV-1-infected patients classified according to the clinical status as asymptomatic carriers (HACs) and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) patients. Bioactive LTB4 and CysLTs were both increased in the plasma and in the supernatant of peripheral blood mononuclear cell cultures of HTLV-1-infected when compared to non-infected. Interestingly, CysLT concentrations were increased in HAM/TSP patients. Also, the concentration of plasma LTB4 and LTC4 positively correlated with the HTLV-1 proviral load in HTLV-1-infected individuals. The gene expression levels of LT receptors were differentially modulated in CD4+ and CD8+ T cells of HTLV-1-infected patients. Analysis of the overall plasma signature of immune mediators demonstrated that LT and chemokine amounts were elevated during HTLV-1 infection. Importantly, in addition to CysLTs, IP-10 was also identified as a biomarker for HAM/TSP activity. These data suggest that LTs are likely to be associated with HTLV-1 infection and HAM/TSP development, suggesting their putative use for clinical monitoring. 相似文献
64.
Wright ND Bahrami B Johnson E Di Malta G Rees G Frith CD Dolan RJ 《Proceedings. Biological sciences / The Royal Society》2012,279(1736):2275-2280
Collaboration can provide benefits to the individual and the group across a variety of contexts. Even in simple perceptual tasks, the aggregation of individuals' personal information can enable enhanced group decision-making. However, in certain circumstances such collaboration can worsen performance, or even expose an individual to exploitation in economic tasks, and therefore a balance needs to be struck between a collaborative and a more egocentric disposition. Neurohumoral agents such as oxytocin are known to promote collaborative behaviours in economic tasks, but whether there are opponent agents, and whether these might even affect information aggregation without an economic component, is unknown. Here, we show that an androgen hormone, testosterone, acts as such an agent. Testosterone causally disrupted collaborative decision-making in a perceptual decision task, markedly reducing performance benefit individuals accrued from collaboration while leaving individual decision-making ability unaffected. This effect emerged because testosterone engendered more egocentric choices, manifest in an overweighting of one's own relative to others' judgements during joint decision-making. Our findings show that the biological control of social behaviour is dynamically regulated not only by modulators promoting, but also by those diminishing a propensity to collaborate. 相似文献
65.
Klopell FC Lemos M Sousa JP Comunello E Maistro EL Bastos JK de Andrade SF 《Zeitschrift für Naturforschung. C, Journal of biosciences》2007,62(7-8):537-542
In this study, the antiulcerogenic effect of essential oil from Baccharis dracunculifolia was evaluated using the model of acute gastric lesions induced by ethanol. The ulcerative lesion index (ULI) was significantly reduced by oral administration of the essential oil of B. dracunculifolia at doses of 50, 250 and 500 mg/kg which reduced the lesions by 42.79, 45.70 and 61.61%, respectively. The analysis of the chemical composition of the essential oil from B. dracunculifolia by GC showed that this was composed mainly of mono- and sesquiterpenes and the majority compound was nerolidol. Therefore, antiulcerogenic activity of nerolidol (50, 250 and 500 mg/kg) was investigated using ethanol-, indomethacin- and stress-induced ulcer models in rat. In the stress-induced ulcer model, a significant reduction of the ULI in animals treated with nerolidol (50, 250 and 500 mg/kg) and cimetidine (100 mg/kg) was observed, compared to the control group (p < 0.05). The percentage of inhibition of ulcer was 41.22, 51.31, 56.57 and 53.50% in groups treated with 50, 250, 500 mg/kg of nerolidol and 100 mg/kg of cimetidine (positive control), respectively. Regarding ethanol- and indomethacin-induced ulcer models, it was observed that the treatment with nerolidol (250 and 500 mg/ kg) significantly reduced the ULI in comparison with the control group (p < 0.05). The dose of 50 mg/kg reduced the parameters analyzed but this was not statistically significant. In the ethanol-induced model percentage of inhibition of ulcer was 34.20, 52.63, 87.63 and 50.87% in groups treated with 50, 250, 500 mg/kg of nerolidol and 30 mg/kg of omeprazol (positive control), respectively. In indomethacin-ulcer the percentage of inhibition of ulcer was 34.69, 40.80, 51.02 and 46.93% in groups treated with 50, 250, 500 mg/kg of nerolidol and 100 mg/ kg of cimetidine (positive control), respectively. The results of this study show that nerolidol displays antiulcer activity, as it significantly inhibited the formation of ulcers induced in different animal models. However, further pharmacological and toxicological investigations, to delineate the mechanism(s) of action and the toxic effects, are required to allow the use of nerolidol for the treatment of gastric ulcer. 相似文献
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A new myxosporean species is described from the fish Semaprochilodus insignis captured from the Amazon River, near Manaus. Myxobolus insignis sp. n. was located in the gills of the host forming plasmodia inside the secondary gill lamellae. The spores had a thick wall (1.5-2 microm) all around their body, and the valves were symmetrical and smooth. The spores were a little longer than wide, with rounded extremities, in frontal view, and oval in lateral view. They were 14.5 (14-15) microm long by 11.3 (11-12) microm wide and 7.8 (7-8) microm thick. Some spores showed the presence of a triangular thickening of the internal face of the wall near the posterior end of the polar capsules. This thickening could occur in one of the sides of the spore or in both sides. The polar capsules were large and equal in size surpassing the midlength of the spore. They were oval with the posterior extremity rounded, and converging anteriorly with tapered ends. They were 7.6 (7-8) microm long by 4.2 (3-5) microm wide, and the polar filament formed 6 coils slightly obliquely to the axis of the polar capsule. An intercapsular appendix was present. There was no mucous envelope or distinct iodinophilous vacuole. 相似文献
68.
The amplitude and the autocorrelation level of the noise affecting the interval between successive electric organ discharges
were estimated in isolated fish and in socially interacting fish of the species Gymnotus carapo. Both quantities increased in the fish with the slower discharging rate of the pair during the interaction, and we aim to
assess whether they have some functional implication for the efficiency of the jamming avoidance response performed by the
fish having the faster discharging rate of the pair. For this purpose, the noisy variability of the intervals around its mean
value was simulated using autoregressive models estimated from experimental recordings of isolated and interacting fish. The
simulation was implemented using two autoregressive models, each representing one fish of the pair. The jamming avoidance
response was included by adding transient interval shortenings to the train simulating the fish of the pair that discharges
at a faster rate whenever the two trains were close to discharge simultaneously. The number of double coincidences (i.e.,
simultaneous discharges occurring in two successive firing cycles) of the two simulated trains was used to measure the efficiency
of the jamming avoidance. This quantity was evaluated separately as a function of the autocorrelation level and amplitude
of the simulated variability, in realizations with and without jamming avoidance response. Only if jamming avoidance response
was included in the simulation have we found that (i) the number of coincidences decreased with the increasing of the autocorrelation
and (ii) the increase in the amplitude determined a growth of the coincidence number at a rate that is inversely proportional
to the autocorrelation level. We argue that the persistent correlations of the fish variability constitute an adaptation that
improves the efficiency of transient interval shortenings as a jamming avoidance strategy. The long autocorrelation time prevents
the disruption of the jamming avoidance performance due to increases in the variability amplitude. 相似文献
69.
A new histozoic species of myxosporean (Henneguya schizodon n. sp.) is described from the Amazon River teleost fish Schizodon fasciatus Spix & Agassiz, 1892 (Characiformes, Anostomidae). The plasmodia, which showed asynchronous development, were located in the kidney of the host. The spore body was ellipsoidal and was 13.1 (12-14) micron long by 3.3 (3-4) micron wide. The total length of the spore was 28.9 (27-30) micron, and each value had a caudal process measuring 16.3 (15-17) micron. The polar capsules were 5.4 (5-6) micron long by 1.3 (1-1.5) micron wide, and each had a polar filament with 8-10 coils. The characteristics of the species were compared with nearly all the species described so far, including all the species reported from South American fishes. This comparison allows to consider the materials as a new species, and the name Henneguya schizodon n. sp. is proposed. 相似文献
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Malta LS Blanchard EB Freidenberg BM Galovski TE Karl A Holzapfel SR 《Applied psychophysiology and biofeedback》2001,26(2):95-116
In the United States, motor vehicle accidents are the leading cause of accidental death and injury. Aggressive driving, which has been identified as a major risk factor for motor vehicle accidents by transportation authorities, is thus an important topic of study. This study compared the physiological reactivity of self-referred aggressive and nonaggressive drivers. Heart rate, blood pressure, facial muscle activity, and skin resistance were monitored as participants listened to idiosyncratic vignettes of driving and fear-provoking scenarios, as well as during a standard stressor task (mental arithmetic). The results were that aggressive drivers exhibited significant increases in muscle tension and blood pressure during the driving vignettes, relative to controls. They also responded to the fear vignette and mental arithmetic in a qualitatively different fashion from that of controls. The aggressive drivers responded to these stimuli with less overall heart rate and electrodermal reactivity, but increased blood pressure and muscle tension. In contrast, the controls responded to the fear vignette and mental arithmetic primarily with increased heart rates and decreased skin resistance. The findings suggest that both physiological hyperarousal as well as differential responses to stressful stimuli may contribute to aggressive driving. Implications for interventions with this population are discussed. 相似文献