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41.
Detailed questioning of 50 patients with uncomplicated migraine has shown that 17 had symptoms that preceded the headache phase by several hours. These prodromes consisted of changes in mood, behaviour, wakefulness, appetite, bowel activity, or fluid balance. The term "complete migraine" is proposed for attacks that include prodromal symptoms, whose occurrence implies an initial diffuse cerebral or hypothalamic disturbance.  相似文献   
42.
In a total of 35 children affected with malignant sufferings (except leucaemias) the haematological-immunological parameters of children surviving for a short time are compared with those surviving for a long time. Compared with children surviving for a short time those surviving for long time had a more "normal" finding initially and during the control examination made after more than 5 years of a survival time which was free of complaints and recidives. The immunologically intact condition of the organism is assumed to be decisive for this course of disease.  相似文献   
43.
Nitrogen fixation and assimilation in nodules and roots were studied in soybean (Glycine max L.) exposed to different levels of aluminium (Al) stress (0, 50, 200 and 500 μM). Al at 500 μM induced oxidative stress, which became evident from an increase in lipid peroxidation accompanied by a concomitant decline in antioxidant enzyme activities and leghaemoglobin breakdown. Consequently, there was also a reduction in nitrogenase activity. However, the leghaemoglobin levels and nitrogenase activity were unexpectedly found to be higher in nodules when the plants were treated with 200 μM Al. Of the enzymes involved in nitrogen assimilation, the activity of glutamate dehydrogenase-NADH was reduced in nodules under Al stress, but it was significantly higher in roots at 500 μM Al as compared to that in the control. In nodules, the glutamine synthetase/glutamate synthase-NADH pathway, assayed in terms of activity and expression of both the enzymes, was inhibited at >50 μM Al; but in roots this inhibitory effect was apparent only at 500 μM Al. No significant changes in ammonium and protein contents were recorded in the nodules or roots when the plants were treated with 50 μM Al. However, Al at ≥200 μM significantly increased the ammonium levels and decreased the protein content in the nodules. But these contrasting effects on ammonium and protein contents due to Al stress were observed in the roots only at 500 μM Al. The results suggest that the effect of Al stress on nitrogen assimilation is more conspicuous in nodules than that in the roots of soybean plants.  相似文献   
44.
Desulfovibrio species are Gram-negative anaerobic sulfate-reducing bacteria that colonize the human gut. Recently, Desulfovibrio spp. have been implicated in gastrointestinal diseases and shown to stimulate the epithelial immune response, leading to increased production of inflammatory cytokines by macrophages. Activated macrophages are key cells of the immune system that impose nitrosative stress during phagocytosis. Hence, we have analyzed the in vitro and in vivo responses of Desulfovibrio vulgaris Hildenborough to nitric oxide (NO) and the role of the hybrid cluster proteins (HCP1 and HCP2) and rubredoxin oxygen oxidoreductases (ROO1 and ROO2) in NO protection. Among the four genes, hcp2 was the gene most highly induced by NO, and the hcp2 transposon mutant exhibited the lowest viability under conditions of NO stress. Studies in murine macrophages revealed that D. vulgaris survives incubation with these phagocytes and triggers NO production at levels similar to those stimulated by the cytokine gamma interferon (IFN-γ). Furthermore, D. vulgaris hcp and roo mutants exhibited reduced viability when incubated with macrophages, revealing that these gene products contribute to the survival of D. vulgaris during macrophage infection.  相似文献   
45.
Ecologists have long investigated why communities are composed of a few common species and many rare species. Most studies relate rarity to either niche differentiation among species or spatial processes. There is a parallel between these processes and the processes proposed to explain the structure of metacommunities. Based on a metacommunity perspective and on data on stream macroinvertebrates from different regions of Brazil, we answer two questions. 1) Are sets of common and rare species affected by similar niche and spatial processes? 2) How does the community composition of common and of rare species differ? The main hypothesis we test is that common species are mainly affected by environmental factors, whereas rare species are mostly influenced by dispersal limitation. We used variation partitioning to determine the proportion of variation explained by the environment and space in common and rare species matrices. Contrary to our expectations, evidence supported the idea that both common and rare species are affected mainly by environmental factors, even after controlling for the differing information content between common and rare species matrices. Moreover, the abundance of some common species is also a good predictor of variation in rare species matrices. Niche differences are unlikely to be the sole cause of patterns of rarity in these metacommunities. We suggest that sets of common and rare species react to similar major environmental gradients and that rare species also respond to processes that operate at a more fine‐grained spatial scale, particularly biotic interactions. We extend the view that species sorting is the dominant process structuring metacommunities and argue that future studies focusing on rarity would benefit from a metacommunity perspective.  相似文献   
46.
Background Gallbladder pathology (GBP) is a relatively uncommon, naturally occurring morbidity in both baboons and humans. Methods A retrospective analysis was performed on 7776 necropsy reports over a 20 year period to determine the prevalence of baboon GBP. Results Ninety‐seven cases of GBP were identified, yielding a 20 year population prevalence of 1.25%. GBP is more common in adult female baboons, occurring with a female to male ratio of nearly 2:1. Among gallbladder pathologies, cholecystitis (35.1%) and cholelithiasis (29.9%) were the most prevalent abnormalities, followed by hyperplasia (16.5%), edema (15.5%), amyloidosis (5.2%), fibrosis (4.1%), necrosis (4.1%), and hemorrhage (1.0%). Conclusion Many epidemiologic similarities exist between GBP in baboons and humans suggesting that the baboon may serve as a reliable animal model system for investigating GBP in humans.  相似文献   
47.
The effect of a natural sesquiterpene ketone, 9,10‐dehydrofukinone (DHF), on pathogenic Staphylococcus aureus and Pseudomonas aeruginosa strains isolated from chronic infectious processes, was the focus of the present study. Lipophilic DHF produced important antibacterial synergistic effects in association with ciprofloxacin (CPX) against two biofilm‐forming strains of S. aureus HT1 (FIC=0.21) and P. aeruginosa HT5 (FIC=0.05). Hence, this mixture constitutes an excellent strategy to combat these biofilm‐producing bacteria that overexpress drug efflux pumps as a resistance mechanism. Additionally, a substantial rise in beneficial Lactobacillus biofilm biomass was determined as a very significant finding of this association. Particularly, a non‐pathogenic biofilm increment of 119 % was quantified when the mixture was added to a probiotic L. acidophilus ATCC SD‐5212 culture. A surface activity enhanced in 71 % with respect to untreated L. acidophilus culture was also generated by the DHF and CPX association, and therefore, a glycoprotein synthesis induction mediated by the mixture is discussed. The results obtained could help in the development of new selective antibiotics. From an ecological standpoint, the present study strongly suggests that DHF is a polyfunctional organic molecule produced with a high yield in Senecio punae that exerts a positive impact on a non‐pathogenic plant bacterium L. plantarum CE105.  相似文献   
48.
Composition of the gut microbiota changes during ageing, but questions remain about whether age is also associated with deficits in microbiome function and whether these changes occur sharply or progressively. The ability to define these deficits in populations of different ages may help determine a chronological age threshold at which deficits occur and subsequently identify innovative dietary strategies for active and healthy ageing. Here, active gut microbiota and associated metabolic functions were evaluated using shotgun proteomics in three well‐defined age groups consisting of 30 healthy volunteers, namely, ten infants, ten adults and ten elderly individuals. Samples from each volunteer at intervals of up to 6 months (n = 83 samples) were used for validation. Ageing gradually increases the diversity of gut bacteria that actively synthesize proteins, that is by 1.4‐fold from infants to elderly individuals. An analysis of functional deficits consistently identifies a relationship between tryptophan and indole metabolism and ageing (p < 2.8e?8). Indeed, the synthesis of proteins involved in tryptophan and indole production and the faecal concentrations of these metabolites are directly correlated (r2 > .987) and progressively decrease with age (r2 > .948). An age threshold for a 50% decrease is observed ca. 11–31 years old, and a greater than 90% reduction is observed from the ages of 34–54 years. Based on recent investigations linking tryptophan with abundance of indole and other “healthy” longevity molecules and on the results from this small cohort study, dietary interventions aimed at manipulating tryptophan deficits since a relatively “young” age of 34 and, particularly, in the elderly are recommended.  相似文献   
49.
Plasmodium falciparum parasites resistant to antimalarial treatments have hindered malaria disease control. Sulfadoxine-pyrimethamine (SP) was used globally as a first-line treatment for malaria after wide-spread resistance to chloroquine emerged and, although replaced by artemisinin combinations, is currently used as intermittent preventive treatment of malaria in pregnancy and in young children as part of seasonal malaria chemoprophylaxis in sub-Saharan Africa. The emergence of SP-resistant parasites has been predominantly driven by cumulative build-up of mutations in the dihydrofolate reductase (pfdhfr) and dihydropteroate synthetase (pfdhps) genes, but additional amplifications in the folate pathway rate-limiting pfgch1 gene and promoter, have recently been described. However, the genetic make-up and prevalence of those amplifications is not fully understood. We analyse the whole genome sequence data of 4,134 P. falciparum isolates across 29 malaria endemic countries, and reveal that the pfgch1 gene and promoter amplifications have at least ten different forms, occurring collectively in 23% and 34% in Southeast Asian and African isolates, respectively. Amplifications are more likely to be present in isolates with a greater accumulation of pfdhfr and pfdhps substitutions (median of 1 additional mutations; P<0.00001), and there was evidence that the frequency of pfgch1 variants may be increasing in some African populations, presumably under the pressure of SP for chemoprophylaxis and anti-folate containing antibiotics used for the treatment of bacterial infections. The selection of P. falciparum with pfgch1 amplifications may enhance the fitness of parasites with pfdhfr and pfdhps substitutions, potentially threatening the efficacy of this regimen for prevention of malaria in vulnerable groups. Our work describes new pfgch1 amplifications that can be used to inform the surveillance of SP drug resistance, its prophylactic use, and future experimental work to understand functional mechanisms.  相似文献   
50.
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