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Mean Prevalence (mean + prevalence)
Selected AbstractsTransmission of neozoic Anguillicoloides crassus and established Camallanus lacustris in ruffe Gymnocephalus cernuusJOURNAL OF FISH BIOLOGY, Issue 9 2008J. Unger In the present study, groups of ruffe Gymnocephalus cernuus, reared singly, were exposed to defined numbers of Anguillicoloides crassus or Camallanus lacustris under controlled laboratory conditions. Infection took place orally through feeding G. cernuus with axenically cultured and laboratory infected copepods, in which the parasites had developed to the infective third stage (L3). Mean prevalence (94·3%) and infection probability (38·5%) for the established C. lacustris were significantly higher than for the neozoic A. crassus (14·3 and 1·0%, respectively). Peripheral blood leukocytes were significantly increased in infected fish, apparently independent of exposure level, parasite species or intensity of infection compared to the controls. In infected fish, the gonado-somatic index (IG) was significantly reduced by c. 50%, and the spleen-somatic index (IS) was significantly increased compared to controls. Both parasites raised similar physiological and immunological responses in G. cernuus, which was able to effectively reject the neozoic A. crassus. [source] Review article: Helicobacter pylori -negative duodenal ulcer diseaseALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 8 2009J. P. GISBERT Aliment Pharmacol Ther,30, 791,815 Summary Background,Helicobacter pylori infection rates in duodenal ulcer (DU) patients may be lower than previously estimated. Aim, To review the real prevalence of H. pylori -negative DUs and its possible causes. Methods, Bibliographical searches in MEDLINE looking for the terms ,H. pylori' and ,duodenal ulcer'. Results, Mean prevalence of H. pylori infection in DU disease, calculated from studies published during the last 10 years including a total of 16 080 patients, was 81%, and this figure was lower (77%) when only the last 5 years were considered. Associations with H. pylori -negative DU were: (1) False negative results of diagnostic methods, (2) NSAID use (21% in studies with <90% infection rate), (3) Complicated DU (bleeding, obstruction, perforation), (4) Smoking, (5) Isolated H. pylori duodenal colonization, (6) Older age, (7) Gastric hypersecretion, (8) Diseases of the duodenal mucosa, (9) Helicobacter,heilmanii' infection and (10) Concomitant diseases. Conclusion, In patients with H. pylori -negative DU disease, one should carefully confirm that the assessment of H. pylori status is reliable. In truly H. pylori -negative patients, the most common single cause of DU is, by far, the use of NSAIDs. Ulcers not associated with H. pylori, NSAIDs or other obvious causes should, for the present, be viewed as ,idiopathic'. True idiopathic DU disease only exceptionally exists. [source] Environmental stresses mediate endophyte,grass interactions in a boreal archipelagoJOURNAL OF ECOLOGY, Issue 2 2010Nora M. Saona Summary 1.,Both evolutionary theory and empirical evidence from agricultural research support the view that asexual, vertically transmitted fungal endophytes are typically plant mutualists that develop high infection frequencies within host grass populations. In contrast, endophyte,grass interactions in natural ecosystems are more variable, spanning the range from mutualism to antagonism and comparatively little is known about their range of response to environmental stress. 2.,We examined patterns in endophyte prevalence and endophyte,grass interactions across nutrient and grazing (from Greylag and Canada geese) gradients in 15 sites with different soil moisture levels in 13 island populations of the widespread grass Festuca rubra in a boreal archipelago in Sweden. 3.,In the field, endophyte prevalence levels were generally low (range = 10,53%) compared with those reported from agricultural systems. Under mesic-moist conditions endophyte prevalence was constantly low (mean prevalence = 15%) and was not affected by grazing pressure or nutrient availability. In contrast, under conditions of drought, endophyte prevalence increased from 10% to 53% with increasing nutrient availability and increasing grazing pressure. 4.,In the field, we measured the production of flowering culms, as a proxy for host fitness, to determine how endophyte-infected plants differed from uninfected plants. At dry sites, endophyte infection did not affect flowering culm production. In contrast, at mesic-moist sites production of flowering culms in endophyte-infected plants increased with the covarying effects of increasing nutrient availability and grazing pressure, indicating that the interaction switched from antagonistic to mutualistic. 5.,A concurrent glasshouse experiment showed that in most situations, the host appears to incur some costs for harbouring endophytes. Uninfected grasses generally outperformed infected grasses (antagonistic interaction), while infected grasses outperformed uninfected grasses (mutualistic interaction) only in dry, nutrient-rich conditions. Nutrient and water addition affected tiller production, leaf number and leaf length differently, suggesting that tillers responded with different strategies. This emphasizes that several response variables are needed to evaluate the interaction. 6.,Synthesis. This study found complex patterns in endophyte prevalence that were not always correlated with culm production. These contrasting patterns suggest that the direction and strength of selection on infected plants is highly variable and depends upon a suite of interacting environmental variables that may fluctuate in the intensity of their impact, during the course of the host life cycle. [source] Prevalence, prevention, and treatment of pressure ulcers: Descriptive study in 89 institutions in The NetherlandsRESEARCH IN NURSING & HEALTH, Issue 2 2002Gerrie J.J.W. Bours Abstract The purpose of the present study was to assess the prevalence of pressure ulcers and the use of Dutch guidelines for the prevention and treatment of pressure ulcers. A survey of 16,344 patients in 89 health care institutions on 1 day showed a mean prevalence of pressure ulcers of 23.1%. It was found that Dutch guidelines on some aspects of prevention and treatment of pressure ulcers were not being followed. Only 53% of the patients who should have been positioned on a support surface were positioned on such a device. Fewer than one-third of the patients who should have been repositioned, should have received nutritional support, or should have been educated received these interventions, and only 33.6% of all pressure ulcers were dressed as recommended. More attention to the dissemination and implementation of the guidelines is needed to reduce this high prevalence of pressure ulcers. © 2002 Wiley Periodicals, Inc. Res Nurs Health 25:99,110, 2002 [source] Prevalence of viral infection detected by PCR and RT-PCR in patients with acute exacerbation of COPD: A systematic reviewRESPIROLOGY, Issue 3 2010Anant MOHAN ABSTRACT Background and objective: Viruses are important aetiological agents of acute exacerbation of COPD (AECOPD). Their reported prevalence varies from region to region. This systematic review calculated the prevalence of respiratory viral infections in AECOPD. Methods: A systematic search was performed using Medline, and references of relevant articles and conference proceedings were hand searched. Articles for review were selected based on the following criteria: (i) prospective or cross-sectional study, (ii) original research, (iii) viral detection used the highly sensitive techniques of PCR and/or Reverse Transcriptase PCR (RT-PCR), (iv) viral prevalence in AECOPD defined, and (v) full paper available in English. We assessed the study quality and extracted data independently and in duplicate using a pre-defined data extraction form. Weighted mean prevalence (WMP) was calculated and a forest plot was constructed to show the dispersion. Results: Eight studies met the inclusion criteria. The WMP of respiratory viral infection in AECOPD was 34.1% (95% CI: 23.9,44.4). picornavirus was the most commonly detected virus with WMP 17.3% (95% CI: 7.2,27.3), followed by influenza; 7.4% (95% CI: 2.9,12.0), respiratory syncytial virus; 5.3% (95% CI: 1.6,9.0), corona viruses; 3.1% (95% CI: 0.4,5.8), parainfluenza; 2.6% (95% CI: 0.4,4.8), adenovirus; 1.1% (95% CI: ,1.1 to 3.3), and human metapneumovirus; 0.7% (95% CI: ,0.3 to 1.8). Maximum WMP was observed in studies from Europe followed by the USA, Australia and Asia. Picorna was the most common virus detected in Western countries whereas influenza was most common in Asia. Conclusions: This systematic review demonstrated that viruses are strongly associated with AECOPD, with the highest detection rates of viruses being in Europe. The geographical epidemiology of viruses may have important therapeutic implications for management of AECOPD. [source] | ||||||||||