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101.
Limited data are available on the fatty acid (FA) composition of circulating lipids and the associations with diet, physiological and pathological conditions, due to the complexity and costs of the analytical process. The aim of our study was to evaluate the FA composition in 108 healthy subjects and to correlate the data with gender, pregnancy, dietary habits, lifestyle, and short-term controlled intake of n-3 FA, using an innovative analytical approach for the collection and processing of blood samples. Ten subjects were also supplemented with n-3 polyunsaturated FA as smoked salmon or capsules for 3 weeks. The resulting blood FA composition was affected by gender, pregnancy, diet and smoking. The data indicate that this new analytical methodology is suitable for assessing associations between circulating FA and various parameters in large population groups, and is applicable to epidemiological studies and in the assessment of the effects of controlled FA supplementation in clinical studies.  相似文献   
102.
Colombo MI 《IUBMB life》2007,59(4-5):238-242
Host cell recognition and eradication of invading pathogens is crucial for the control of microbial infections. However, several microorganisms develop tactics that allow them to survive intracellularly. Autophagy, a process involved in protein turnover and in charge of the removal of aged organelles by degradation of engulfed cytoplasmic portions, was recently shown to play a clear role in the detection and elimination of intracellular pathogens. Yet, some pathogens employ elegant strategies to elude entrapment in autophagosomes, and thus to avoid lysosomal degradation, whereas others utilize the autophagy pathway for their own benefit. In this review some recent findings on the relationship between microorganisms and autophagy are summarized, the underlying assumption being that intracellular infection models may contribute to the understanding of the molecular mechanisms involved in the autophagic process.  相似文献   
103.
104.
Forest restoration by planting trees often accelerates succession, but the trajectories toward reference ecosystems have rarely been evaluated. Using a chronosequence (4–53 years) of 26 riparian forest undergoing restoration in the Brazilian Atlantic Forest, we modeled how the variables representing forest structure, tree species richness and composition, and the proportion of plant functional guilds change through time. We also estimated the time required for these variables to reach different types of reference ecosystems: old‐growth forest (OGF), degraded forest, and secondary forest. Among the attributes which follow a predictable trajectory over time are: the basal area, canopy cover, density and tree species richness, as well as proportions of shade tolerant and slow growing species or individuals. Most of the variation in density of pteridophythes, lianas, shrubs and phorophythes, proportion of animal‐dispersed individuals, rarefied richness and floristic similarity with reference ecosystems remain unexplained. Estimated time to reach the reference ecosystems is, in general, shorter for structural attributes than for species composition or proportion of functional guilds. The length of this time varies among the three types of reference ecosystems for most attributes. For instance, tree species richness and proportion of shade tolerant or slow growing individuals become similar to secondary forests in about 40 years, but is estimated to take 70 years or more to reach the OGF. Of all the variables considered, canopy cover, basal area, density, and richness of the understory—by their ecological relevance and predictability—are recommended as ecological indicators for monitoring tropical forest restoration success.  相似文献   
105.
Variations in photosynthesis still cause substantial uncertainties in predicting photosynthetic CO2 uptake rates and monitoring plant stress. Changes in actual photosynthesis that are not related to greenness of vegetation are difficult to measure by reflectance based optical remote sensing techniques. Several activities are underway to evaluate the sun‐induced fluorescence signal on the ground and on a coarse spatial scale using space‐borne imaging spectrometers. Intermediate‐scale observations using airborne‐based imaging spectroscopy, which are critical to bridge the existing gap between small‐scale field studies and global observations, are still insufficient. Here we present the first validated maps of sun‐induced fluorescence in that critical, intermediate spatial resolution, employing the novel airborne imaging spectrometer HyPlant. HyPlant has an unprecedented spectral resolution, which allows for the first time quantifying sun‐induced fluorescence fluxes in physical units according to the Fraunhofer Line Depth Principle that exploits solar and atmospheric absorption bands. Maps of sun‐induced fluorescence show a large spatial variability between different vegetation types, which complement classical remote sensing approaches. Different crop types largely differ in emitting fluorescence that additionally changes within the seasonal cycle and thus may be related to the seasonal activation and deactivation of the photosynthetic machinery. We argue that sun‐induced fluorescence emission is related to two processes: (i) the total absorbed radiation by photosynthetically active chlorophyll; and (ii) the functional status of actual photosynthesis and vegetation stress.  相似文献   
106.

Background

The aetiopathogenesis of chronic rhinosinusitis with nasal polyps (CRSwNP) is still unknown. The role of atopy and the concept of united airways in such patients are still a matter of debate. In this pilot study we aimed at evaluating the degree of eosinophilic inflammation and the frequency of atopy in a cohort of CRSwNP patients candidate for Functional Endoscopic Sinus Surgery (FESS) and assessing the association between these factors and relapsing forms of CRSwNP.

Methods

30 patients (18 men, 12 women) with CRSwNP eligible for FESS were evaluated before and after surgery. Preoperative investigation included: history of previous relapse after FESS, clinical and laboratory allergologic assessment, spirometry, methacholine challenge, blood eosinophilia and determination of the fraction of nitric oxide in exhaled air (FeNO). Nasal fibroendoscopy, spirometry and FeNO determination were also assessed prospectively at 3 and 27 months post-FESS.

Results

18/30 subjects were atopic, 6/18 (33 %) were monosensitized, 16/30 (53 %) were asthmatics and 10/30 (33 %) had non steroidalantinflammatory drugs (NSAIDs) hypersensitivity. Twenty-one patients (70 %) were classified as relapsers, 15/18 (83 %) among atopics, 6/12 (50 %) among non atopics (p = 0.05). Among patients with NSAIDs hypersensitivity, 9/10 (90 %) were relapsers. The median IgE concentration was 161.5 UI/mL in relapsers and 79 UI/mL in non-relapsers (ns). The mean FeNO decreased after FESS (43.1–26.6 ppb) in 84 % of patients, but this effect disappeared over time (FeNO = 37.7 ppb at 27 months). Higher levels of FeNO pre-FESS were detected in atopics, and in particular in relapsing ones (median 51.1 ppb vs 22.1, ns). Higher levels of FeNO pre-FESS were detected in asthmatic patients, especially in those who relapsed (median: 67 vs 64.85 ppb in non-relapsed patients, ns). The Tiffeneau Index (FEV1/FVC) was significantly lower in asthmatic relapsers than in non relapsers asthmatics (94.7 ± 11.1 versus 105 ± 5.9—p = 0.04). Patients with asthma and atopy had a major risk of relapse (p = 0.05).

Conclusion

In our pilot study, atopy, severe asthma, bronchial inflammation, NSAIDs hypersensitivity and high level of total IgE are possible useful prognostic factors for the proneness to relapse after FESS. The role of allergy in CRSwNP pathogenesis should consequently be given deeper consideration. Allergen specific immunotherapy, combined with anti-IgE therapy, may have an immunomodulatory effect preventing polyps relapse and need to be investigated.

Electronic supplementary material

The online version of this article (doi:10.1186/s12948-015-0026-8) contains supplementary material, which is available to authorized users.  相似文献   
107.
In seed plant ovules, the diploid maternal sporophytic generation embeds and sustains the haploid generation (the female gametophyte); thus, two independent generations coexist in a single organ. Many independent studies on Arabidopsis ovule mutants suggest that embryo sac development requires highly synchronized morphogenesis of the maternal sporophyte surrounding the gametophyte, since megagametogenesis is severely perturbed in most of the known sporophytic ovule development mutants. Which are the messenger molecules involved in the haploid–diploid dialogue? And furthermore, is this one way communication or is a feedback cross talk? In this review, we discuss genetic and molecular evidences supporting the presence of a cross talk between the two generations, starting from the first studies regarding ovule development and ending to the recently sporophytic identified genes whose expression is strictly controlled by the haploid gametophytic generation. We will mainly focus on Arabidopsis studies since it is the species more widely studied for this aspect. Furthermore, possible candidate molecules involved in the diploid–haploid generations dialogue will be presented and discussed.  相似文献   
108.
Colon cancer is the fourth most common cancer globally with 639,000 deaths reported annually. Typical chemotherapy is provided by injection route to reduce tumor growth and metastasis. Recent research investigates the oral delivery profiles of chemotherapeutic agents. In comparison to injection, oral administration of drugs in the form of a colon-specific delivery system is expected to increase drug bioavailability at target site, reduce drug dose and systemic adverse effects. Pectin is suitable for use as colon-specific drug delivery vehicle as it is selectively digested by colonic microflora to release drug with minimal degradation in upper gastrointestinal tract. The present review examines the physicochemical attributes of formulation needed to retard drug release of pectin matrix prior to its arrival at colon, and evaluate the therapeutic value of pectin matrix in association with colon cancer. The review suggests that multi-particulate calcium pectinate matrix is an ideal carrier to orally deliver drugs for site-specific treatment of colon cancer as (1) crosslinking of pectin by calcium ions in a matrix negates drug release in upper gastrointestinal tract, (2) multi-particulate carrier has a slower transit and a higher contact time for drug action in colon than single-unit dosage form, and (3) both pectin and calcium have an indication to reduce the severity of colon cancer from the implication of diet and molecular biology studies. Pectin matrix demonstrates dual advantages as drug carrier and therapeutic for use in treatment of colon cancer.  相似文献   
109.
Slot machines are the most common and addictive form of gambling. In the current study, we recorded from single neurons in the 'prefrontal cortex' of pigeons while they played a slot-machine-like task. We identified four categories of neurons that coded for different aspects of our slot-machine-like task. Reward-Proximity neurons showed a linear increase in activity as the opportunity for a reward drew near. I-Won neurons fired only when the fourth stimulus of a winning (four-of-a-kind) combination was displayed. I-Lost neurons changed their firing rate at the presentation of the first nonidentical stimulus, that is, when it was apparent that no reward was forthcoming. Finally, Near-Miss neurons also changed their activity the moment it was recognized that a reward was no longer available, but more importantly, the activity level was related to whether the trial contained one, two, or three identical stimuli prior to the display of the nonidentical stimulus. These findings not only add to recent neurophysiological research employing simulated gambling paradigms, but also add to research addressing the functional correspondence between the avian NCL and primate PFC.  相似文献   
110.
Accumulation of β-sheet-rich peptide (Aβ) is strongly associated with Alzheimer's disease, characterized by reduction in synapse density, structural alterations of dendritic spines, modification of synaptic protein expression, loss of long-term potentiation and neuronal cell death. Aβ species are potent neurotoxins, however the molecular mechanism responsible for Aβ toxicity is still unknown. Numerous mechanisms of toxicity were proposed, although there is no agreement about their relative importance in disease pathogenesis. Here, the toxicity of Aβ 1-40 and Aβ 1-42 monomers, oligomers or fibrils, was evaluated using the N2a cell line. A structure-function relationship between peptide aggregation state and toxic properties was established. Moreover, we demonstrated that Aβ toxic species cross the plasma membrane, accumulate in cells and bind to a variety of internal proteins, especially on the cytoskeleton and in the endoplasmatic reticulum (ER). Based on these data we suggest that numerous proteins act as Aβ receptors in N2a cells, triggering a multi factorial toxicity.  相似文献   
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