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1.
The callitrichids are non-human primates that feed on insects and plant matter in nature, but in captivity, they are fed mostly an artificial diet containing amounts of gluten, in their toxic forms in items such as wheat, barley and rye. The aim of this research was to estimate the blood β-defensin and Toll like receptor 5 (TLR5) gene expressions and to analyze the stool consistency (firm, soft, diarrheic) in Leontocebus fuscicollis raised in captivity. Blood samples of animals under gluten-free and gluten diets were collected and their fecal output quality was periodically monitored and classified during the course of the study. Gene expression was evaluated using real-time PCR. The stool consistencies of individuals fed a gluten diet were most frequently soft or diarrheic, while it was mostly normal in individuals fed a gluten-free diet. β-Defensin expression increased in individuals fed a gluten diet, but decreased after 15 days. Expression normalized between 30 and 45 days on a gluten-free diet. However, expression of the TLR5 gene did not change under a gluten diet. A gluten diet affects stool quality, and brings about an immediate increase in blood β-defensin expression in the beginning but decreases after 15 days. 相似文献
2.
Krill ( Euphausiids) play a vital ecosystem role in many of the world’s most productive marine regions, providing an important trophic linkage. We introduce a robust modeling approach to link Cassin’s auklet ( Ptychoramphus aleuticus) abundance and distribution to large-scale and local oceanic and atmospheric conditions and relate these patterns to similarly modeled distributions of an important prey resource, krill. We carried out at-sea strip transect bird surveys and hydroacoustic assessments of euphausiids (2004–2013). Data informed separate, spatially-explicit predictive models of Cassin’s auklet abundance (zero-inflated negative binomial regression) and krill biomass (two-part model) based on these surveys. We established the type of prey responsible for acoustic backscatter by conducting net tows of the upper 50 m during surveys. We determined the types of prey fed to Cassin’s auklet chicks by collecting diet samples from provisioning adults. Using time-depth-recorders, we found Cassin’s auklets utilized consistent areas in the upper water column, less than 30 m, where krill could be found (99.5% of dives were less than 30 m). Birds primarily preyed upon two species of euphausiids, Euphausia pacifica and Thysanoessa spinifera, which were available in the upper water column. Cassin’s auklet abundance was best predicted by both large scale and localized oceanic processes (upwelling) while krill biomass was best predicted by local factors (temperature, salinity, and fluorescence) and both large scale and localized oceanic processes (upwelling). Models predicted varying krill and bird distribution by month and year. Our work informs the use of Cassin’s auklet as a valuable indicator or krill abundance and distribution and strengthens our understanding of the link between Cassin’s auklet and its primary prey. We expect future increases in frequency and magnitude of anomalous ocean conditions will result in decreased availability of krill leading to declines in the Farallon Islands population of Cassin’s auklets. 相似文献
3.
Environment, sex, and age are the main factors which determine the elemental composition of hair. The objective of the study is to determine the contents of calcium (Ca), magnesium (Mg), zinc (Zn), copper (Cu), iron (Fe), lead (Pb), and cadmium (Cd) in girls’ and boys’ hair in five age groups (within 1–19-year range) corresponding to successive human ontogenesis phases as well as to evaluate the relationships between these elements. Quantitative analysis has been carried out using atomic absorption spectrometry (AAS). Experimental results were analyzed using classic and principal component (PCA) statistical analyses. In particular, differences between contents of particularly Ca, Mg, and Zn in girls’ and boys’ hair were found, and substantial differences between age groups were stated. In general, larger amounts of Ca, Mg, and Zn as compared to boys’ hair have been observed for girls’ hair and higher toxic element (Pb, Cd) contents for boys were measured in some age groups. An increasing trend was found for bioelements (Ca, Mg, Zn) both for girls and boys in all age groups, while for Cu and Fe content, changes are insignificant and even decreasing for teenagers. The most frequently correlating element pairs are Ca–Mg, Ca–Zn, Mg–Zn, and Pb–Cd. Classic and PCA statistics show, in general, a satisfactory consistence. The elemental composition of hair varies depending on the gender and age of children and young people. 相似文献
4.
Although some epidemiological investigations showed a potential association between long-term exposure of extremely low frequency electromagnetic fields (ELF-EMF) and Alzheimer’s disease (AD), no reasonable mechanism can explain this association, and the related animal experiments are rare. In this study, ELF-EMF exposure (50Hz 400µT 60d) combined with D-galactose intraperitoneal (50mg/kg, q.d., 42d) and Aβ 25–35 hippocampal (5μl/unilateral, bilateral, single-dose) injection was implemented to establish a complex rat model. Then the effects of ELF-EMF exposure on AD development was studied by using the Morris water maze, pathological analysis, and comparative proteomics. The results showed that ELF-EMF exposure delayed the weight gain of rats, and partially improved cognitive and clinicopathologic symptoms of AD rats. The differential proteomic analysis results suggest that synaptic transmission, oxidative stress, protein degradation, energy metabolism, Tau aggregation, and inflammation involved in the effects mentioned above. Therefore, our findings indicate that certain conditions of ELF-EMF exposure could delay the development of AD in rats. 相似文献
6.
Deficits in hippocampal synaptic plasticity result in cognitive impairment in Huntington’s disease (HD). Pituitary adenylate cyclase-activating polypeptide (PACAP) is a neuropeptide that exerts neuroprotective actions, mainly through the PAC1 receptor. However, the role of PACAP in cognition is poorly understood, and no data exists in the context of Huntington’s disease (HD). Here, we investigated the ability of PACAP receptor stimulation to enhance memory development in HD. First, we observed a hippocampal decline of all three PACAP receptor expressions, i.e., PAC1, VPAC1, and VPAC2, in two different HD mouse models, R6/1 and HdhQ7/Q111, from the onset of cognitive dysfunction. In hippocampal post-mortem human samples, we found a specific decrease of PAC1, without changes in VPAC1 and VPAC2 receptors. To determine whether activation of PACAP receptors could contribute to improve memory performance, we conducted daily intranasal administration of PACAP38 to R6/1 mice at the onset of cognitive impairment for seven days. We found that PACAP treatment rescued PAC1 level in R6/1 mice, promoted expression of the hippocampal brain-derived neurotrophic factor, and reduced the formation of mutant huntingtin aggregates. Furthermore, PACAP administration counteracted R6/1 mice memory deficits as analyzed by the novel object recognition test and the T-maze spontaneous alternation task. Importantly, the effect of PACAP on cognitive performance was associated with an increase of VGlut-1 and PSD95 immunolabeling in hippocampus of R6/1 mice. Taken together, these results suggest that PACAP, acting through stimulation of PAC1 receptor, may have a therapeutic potential to counteract cognitive deficits induced in HD. 相似文献
7.
Cooperation is one of the essential factors for all biological organisms in major evolutionary transitions. Recent studies have investigated the effect of migration for the evolution of cooperation. However, little is known about whether and how an individuals’ cooperativeness coevolves with mobility. One possibility is that mobility enhances cooperation by enabling cooperators to escape from defectors and form clusters; the other possibility is that mobility inhibits cooperation by helping the defectors to catch and exploit the groups of cooperators. In this study we investigate the coevolutionary dynamics by using the prisoner’s dilemma game model on a lattice structure. The computer simulations demonstrate that natural selection maintains cooperation in the form of evolutionary chasing between the cooperators and defectors. First, cooperative groups grow and collectively move in the same direction. Then, mutant defectors emerge and invade the cooperative groups, after which the defectors exploit the cooperators. Then other cooperative groups emerge due to mutation and the cycle is repeated. Here, it is worth noting that, as a result of natural selection, the mobility evolves towards directional migration, but not to random or completely fixed migration. Furthermore, with directional migration, the rate of global population extinction is lower when compared with other cases without the evolution of mobility (i.e., when mobility is preset to random or fixed). These findings illustrate the coevolutionary dynamics of cooperation and mobility through the directional chasing between cooperators and defectors. 相似文献
8.
Amyloid precursor protein cleaving enzyme 1 (BACE1), an aspartyl protease, initiates processing of the amyloid precursor protein (APP) into β-amyloid (Aβ); the peptide likely contributes to development of Alzheimer’s disease (AD). BACE1 is an attractive therapeutic target for AD treatment, but it exhibits other physiological activities and has many other substrates besides APP. Thus, inhibition of BACE1 function may cause adverse side effects. Here, we present a peptide, S1, isolated from a peptide library that selectively inhibits BACE1 hydrolytic activity by binding to the β-proteolytic site on APP and Aβ N-terminal. The S1 peptide significantly reduced Aβ levels in vitro and in vivo and inhibited Aβ cytotoxicity in SH-SY5Y cells. When applied to APPswe/PS1dE9 double transgenic mice by intracerebroventricular injection, S1 significantly improved the spatial memory as determined by the Morris Water Maze, and also attenuated their Aβ burden. These results indicate that the dual-functional peptide S1 may have therapeutic potential for AD by both reducing Aβ generation and inhibiting Aβ cytotoxicity. 相似文献
9.
The primary structure of adult marmoset hemoglobin has been determined. The - and -chains of HbA were separated on a CM23 column in 8 M urea using a sodium phosphate gradient. Tryptic digests of the - and -chains were fractionated on a Dowex 50W-X2 column using a pH and pyridine acetate gradient. Large peptide fragments were obtained by the cyanogen bromide cleavage of the - and -chains, as well as by tryptic digestion of the maleylated - and -chains. The sequence was derived from the amino acid compositions and sequences of the individual tryptic peptide, automated sequence determination of intact - and -chains, as well as automated sequence determination of cyanogen bromide fragments and tryptic maleylated peptides derived from the - and -chains. The complete structure of marmoset adult hemoglobin is closely homologous to that of other primate hemoglobins. The sequence of the marmoset -chain differs from the -chain of human HbA at positions 8, 19, 23, 68, and 116. The -chain from marmoset HbA differs from the -chain of human HbA at positions 5, 13, 21, 50, 87, and 125.This work was supported in part by funds from a Physicians' Medical Education and Research Foundation Grant of the University of Tennessee Memorial Research Hospital and by NIH General Research Support Grant FR-5541 to the institution. 相似文献
10.
Neurochemical Research - The bidirectional communication between the brain and peripheral organs have been widely documented, but the impact of visceral adipose tissue (VAT) dysfunction and its... 相似文献
11.
The exact mechanism of gut dysfunction in Parkinson’s disease and, conversely, the role of gut pathology in brain dopaminergic degeneration are controversial. We investigated the effects of nigral lesions on the colonic neurotransmission, the effect of gut inflammation on the nigrostriatal dopaminergic function, and the possible involvement of the vagus nerve and the local renin-angiotensin system (RAS). Nigrostriatal dopamine depletion was performed by bilateral injection 6-hydroxydopamine, and gut inflammation was induced by dextran sulfate sodium salt treatment in rats and mice, respectively, with or without vagal disruption. A decrease in central dopamine levels induced a decrease in colonic dopamine types 1 and 2 receptor expression together with an increase in the colonic levels of dopamine and a decrease in the levels of acetylcholine, which may explain a decrease in gut motility. Central dopaminergic depletion also induced an increase in the colonic levels of inflammatory and oxidative stress markers together with activation of the pro-inflammatory arm of the local RAS. Mice with acute (1 week) or subchronic (3 weeks) gut inflammation did not show a significant increase in colonic α-synuclein and phosphorylated α-synuclein expression during this relatively short survival period. Interestingly, we observed early changes in the nigrostriatal dopaminergic homeostasis, dopaminergic neuron death, and increased levels of nigral pro-inflammatory markers and RAS pro-inflammatory activity. The present results show that a dysregulation of the neural bidirectional gut-brain interaction may explain the early gut disturbances observed in parkinsonian patients, and also the increase in vulnerability of nigral dopaminergic neurons after gut inflammation. 相似文献
13.
Clinicians aim to establish trust during medical encounters because, without it, health consumers may not seek medical care,
consider their diagnoses legitimate, or adhere to treatment regimens. This paper examines the identification and treatment
of memory loss within two specialty clinics to understand how cultural dynamics, such as organizational ethos and work practices,
influence the social fabric of cognitive evaluations. Ethnographic data suggest important historical and cultural differences
in the approaches to Alzheimer’s disease (AD). Organizational routines, however, support a common goal, that of moving individuals
from “potential patients” to patients, and ultimately research subjects, through establishing trust. Although the processes
through which trust is potentially achieved, or the social conditions of trust, were similar at the sites, the object of trust was different. Whereas one clinic encouraged trust in collective medical
expertise, the other focused on trust in specific clinicians. These conditions affect the clinical consequences of trust, particularly how and when the diagnosis is delivered, use of the AD label and other terminology, and the level
of standardization. The individual
consequences include perceptions of patients and depictions of the prognosis. Whether cognitive impairment is viewed as a scientific puzzle
to be solved or is seen as a chronic illness significantly shapes the organizational processes of clinical evaluation. Alzheimer’s
disease, as a cultural object, is a particularly salient exemplar of the clinical negotiation of ambiguous diagnostic categorizations
and the unpredictable patient in daily biomedical practice.
相似文献
15.
The critical pathological feature of Alzheimer’s disease (AD) is the accumulation of β-amyloid (Aβ), the main constituent of amyloid plaques. β-amyloid precursor protein (APP) undergoes amyloidogenic cleavage by β- and γ-secretase generating Aβ at endosomes or non-amyloidogenic processing by α-secretase precluding the production of Aβ at the plasma membrane. Recently, several natural products have been widely researched on the prevention of Aβ accumulation for AD treatment. We previously reported that Lycoris chejuensis K. Tae et S. Ko (CJ), which originated from Jeju Island in Korea, improved the disrupted memory functions and reduced Aβ production in vivo. Here, we further explored the effect of its active component, 7-deoxy-trans-dihydronarciclasine (coded as E144), on Aβ generation and the underlying mechanism. Our results showed that E144 reduced the level of APP, especially its mature form, in HeLa cells overexpressing human APP with the Swedish mutation. Concomitantly, E144 decreased the levels of Aβ, sAPPβ, sAPPα, and C-terminal fragment. In addition, administration of E144 normalized the behavioral deficits in Tg2576 mice, an APP transgenic mouse model of AD. E144 also decreased the Aβ and APP levels in the cerebral cortex of Tg2576 mice. Thus, we propose that E144 could be a potential drug candidate for an anti-amyloid disease-modifying AD therapy. 相似文献
17.
Human cerebrospinal fluid (CSF), produced by the choroid plexus and secreted into the brain ventricles and subarachnoid space, plays critical roles in intra-cerebral transport and the biophysical and immune protection of the brain. CSF composition provides valuable insight into soluble pathogenic bio-markers that may be diagnostic for brain disease. In these experiments we analyzed amyloid beta (Aβ) peptide and micro RNA (miRNA) abundance in CSF and in short post-mortem interval (PMI <2.1 hr) brain tissue-derived extracellular fluid (ECF) from Alzheimer’s disease (AD) and age-matched control neocortex. There was a trend for decreased abundance of Aβ42 in the CSF and ECF in AD but it did not reach statistical significance (mean age ~72 yr; N=12; p~0.06, ANOVA). The most abundant nucleic acids in AD CSF and ECF were miRNAs, and their speciation and inducibility were studied further. Fluorescent miRNA-array-based analysis indicated significant increases in miRNA-9, miRNA-125b, miRNA-146a, miRNA-155 in AD CSF and ECF (N=12; p<0.01, ANOVA). Primary human neuronal-glial (HNG) cell co-cultures stressed with AD-derived ECF also displayed an up-regulation of these miRNAs, an effect that was quenched using the anti-NF-кB agents caffeic acid phenethyl ester (CAPE) or 1-fluoro-2-[2-(4-methoxy-phenyl)-ethenyl]-benzene (CAY10512). Increases in miRNAs were confirmed independently using a highly sensitive LED-Northern dot-blot assay. Several of these NF-кB-sensitive miRNAs are known to be up-regulated in AD brain, and associate with the progressive spreading of inflammatory neurodegeneration. The results indicate that miRNA-9, miRNA-125b, miRNA-146a and miRNA-155 are CSF- and ECF-abundant, NF-кB-sensitive pro-inflammatory miRNAs, and their enrichment in circulating CSF and ECF suggest that they may be involved in the modulation or proliferation of miRNA-triggered pathogenic signaling throughout the brain and central nervous system (CNS). 相似文献
18.
The trophic ecology of Kuhl’s pipistrelle Pipistrellus kuhlii (Kuhl, 1817) was investigated monthly from May to October 1999. Nine insect and two arachnid orders were identified in faeces and classified in 24 different categories. The most frequently occurring prey categories were Culicidae, Lepidoptera, Chironomidae/Ceratopogonidae, Hymenoptera, unidentified Brachycera, Tipulidae and unidentified Coleoptera in decreasing order. Other categories exhibited seasonal importance, such as the coleopteran Rhizotrogus sp. Prey availability was evaluated monthly using Malaise traps in known feeding areas. Bats preyed selectively through a temporarily changing pattern. Some taxa constituted an important part of the diet and were positively selected either monthly or in most of the months. Many of them were the largest prey featuring in the diet and changes of their relative profitability across time would determine their selection index. The small size of some prey categories as well as P.kuhlii’s morphofunctional constraints relative to flight and echolocation could explain their underexploitation or rejection. Our results suggest that P. kuhlii could be regarded as a ‘selective opportunist’ species. 相似文献
19.
In the context of 1960s research on biological membranes, scientists stumbled upon a curiously coloured material substance, which became called the “purple membrane.” Interactions with the material as well as chemical analyses led to the conclusion that the microbial membrane contained a photoactive molecule similar to rhodopsin, the light receptor of animals’ retinae. Until 1975, the find led to the formation of novel objects in science, and subsequently to the development of a field in the molecular life sciences that comprised biophysics, bioenergetics as well as membrane and structural biology. Furthermore, the purple membrane and bacteriorhodopsin, as the photoactive membrane transport protein was baptized, inspired attempts at hybrid bio-optical engineering throughout the 1980s. A central motif of the research field was the identification of a functional biological structure, such as a membrane, with a reactive material substance that could be easily prepared and manipulated. Building on this premise, early purple membrane research will be taken as a case in point to understand the appearance and transformation of objects in science through work with material substances. Here, the role played by a perceptible material and its spontaneous change of colour, or reactivity, casts a different light on objects and experimental practices in the late twentieth century molecular life sciences. With respect to the impact of chemical working and thinking, the purple membrane and rhodopsins represent an influential domain straddling the life and chemical sciences as well as bio- and material technologies, which has received only little historical and philosophical attention. Re-drawing the boundary between the living and the non-enlivened, these researches explain and model organismic activity through the reactivity of macromolecular structures, and thus palpable material substances. 相似文献
20.
Anuran ears function as pressure difference receivers, and the amplitude and phase of tympanum vibrations are inherently directional, varying with sound incident angle. We quantified the nature of this directionality for Cope’s gray treefrog, Hyla chrysoscelis. We presented subjects with pure tones, advertisement calls, and frequency-modulated sweeps to examine the influence of frequency, signal level, lung inflation, and sex on ear directionality. Interaural differences in the amplitude of tympanum vibrations were 1–4 dB greater than sound pressure differences adjacent to the two tympana, while interaural differences in the phase of tympanum vibration were similar to or smaller than those in sound phase. Directionality in the amplitude and phase of tympanum vibration were highly dependent on sound frequency, and directionality in amplitude varied slightly with signal level. Directionality in the amplitude and phase of tone- and call-evoked responses did not differ between sexes. Lung inflation strongly affected tympanum directionality over a narrow frequency range that, in females, included call frequencies. This study provides a foundation for further work on the biomechanics and neural mechanisms of spatial hearing in H. chrysoscelis, and lends valuable perspective to behavioral studies on the use of spatial information by this species and other frogs. 相似文献
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