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101.
G. Emerens Wensink Annelot F. Schoffelen Hugo A. Tempelman Maarten B. Rookmaaker Andy I. M. Hoepelman Roos E. Barth 《PloS one》2015,10(8)
Context
As life expectancy improves among Human Immunodeficiency Virus (HIV) patients, renal and cardiovascular diseases are increasingly prevalent in this population. Renal and cardiovascular disease are mutual risk factors and are characterized by albuminuria. Understanding the interactions between HIV, cardiovascular risk factors and renal disease is the first step in tackling this new therapeutic frontier in HIV.Methods
In a rural primary health care centre, 903 HIV-infected adult patients were randomly selected and data on HIV-infection and cardiovascular risk factors were collected. Glomerular filtration rate (eGFR) was estimated. Albuminuria was defined as an Albumin-Creatinine-Ratio above 30 mg/g. Multivariate logistic regression analysis was used to analyse albuminuria and demographic, clinical and HIV-associated variables.Results
The study population consisted of 903 HIV-infected patients, with a median age of 40 years (Inter-Quartile Range (IQR) 34–48 years), and included 625 (69%) women. The median duration since HIV diagnosis was 26 months (IQR 12–58 months) and 787 (87%) received antiretroviral therapy. Thirty-six (4%) of the subjects were shown to have diabetes and 205 (23%) hypertension. In the cohort, 21% had albuminuria and 2% an eGFR <60 mL/min/1.73m2. Albuminuria was associated with hypertension (adjusted odds ratio (aOR) 1.59; 95% confidence interval (CI) 1.05–2.41; p<0.05), total cholesterol (aOR 1.31; 95% CI 1.11–1.54; p<0.05), eGFR (aOR 0.98; 95% CI 0.97–0.99; p<0.001) and detectable viral load (aOR 2.74; 95% CI 1.56–4.79; p<0.001). Hypertension was undertreated: 78% were not receiving treatment, while another 11% were inadequately treated. No patients were receiving lipid-lowering medication.Conclusion
Glomerular filtration rate was well conserved, while albuminuria was common amongst HIV-infected patients in rural South Africa. Both cardiovascular and HIV-specific variables were associated with albuminuria. Improved cardiovascular risk prevention as well as adequate virus suppression might be the key to escape the vicious circle of renal failure and cardiovascular disease and improve the long-term prognosis of HIV-infected patients. 相似文献102.
Maarten A. Jongsma Fred Gould Mathieu Legros Limei Yang Joop J. A. van Loon Marcel Dicke 《Evolutionary ecology》2010,24(5):1017-1030
The major lepidopteran insect pests of cotton and maize harbor intra-specific variation for behavior determining the selection
of host plants for oviposition. Yet, the consequences of behavioral adaptation for fitness have neither been modeled nor monitored
for Bt cotton and maize crops, the most widely grown transgenic herbivore-resistant plants. Here, we present a general two-locus
heuristic model to examine potential outcomes of natural selection when pest populations initially have low frequencies of
alleles for both physiological and behavioral adaptation to Bt crops. We demonstrate that certain ecological conditions allow for the evolution of behavioral choices favoring alternative
oviposition hosts that limit the increase in resistance alleles, even when they are phenotypically dominant. These results
have implications for current refuge policies, which should be adapted to promote the evolution of certain behavioral choices
for alternative oviposition hosts in addition to dilution of physiological resistance alleles. Collection of data on oviposition
host preference as a component of monitoring schemes will provide important insights into mechanisms underlying the durability
of Bt-transgenic host-plant resistance. 相似文献
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107.
Differential effects of nutrient-limited primary production on primary, secondary or tertiary consumers 总被引:2,自引:0,他引:2
Arne M. Malzahn Florian Hantzsche Katherina L. Schoo Maarten Boersma Nicole Aberle 《Oecologia》2010,162(1):35-48
Nutritional imbalances between predator and prey are the rule rather than the exception at the lower end of food webs. We investigated the role of different grazers in the propagation of nutritionally imbalanced primary production by using the same primary producers in a three-trophic-level food chain and a four-trophic-level food chain experimental setup. The three-trophic-level food chain consisted of a classic single-cell primary producer (Rhodomonas salina), a metazoan grazer (the copepod Acartia tonsa) and a top predator (the jellyfish Gonionemus vertens), while we added a protozoan grazer (Oxyrrhis marina) as primary consumer to the food chain to establish the four-trophic-level food chain. This setup allowed us to investigate how nutrient-limitation effects change from one trophic level to another, and to investigate the performance of two components of our experimental food chains in different trophic positions. Stoichiometry and fatty acid profiles of the algae showed significant differences between the nutrient-depleted [no N and no P addition (?P), respectively] and the nutrient-replete (f/2) treatments. The differences in stoichiometry could be traced when O. marina was the first consumer. Copepods feeding on these flagellates were not affected by the nutritional imbalance of their prey in their stoichiometry, their respiration rates nor in their developmental rates. In contrast, when copepods were the primary consumer, those reared on the ?P algae showed significantly higher respiration rates along with significantly lower developmental rates. In neither of our two experimental food chains did the signals from the base of the food chains travel up to jelly fish, our top predator. 相似文献
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As seston and chlorophyll concentrations in eutrophic lakesare usually high all year round, it was hypothesized in thepast that food limitation is of major importance for the seasonaldynamics of herbivorous zooplankton in such lakes. Since directmeasurements of food are hampered by the lack of knowledge onthe exact nature of the food in eutrophic conditions, indirectmeasurements are necessary to estimate the degree of food limitationin these circumstances. Hence, we used laboratory- and field-derivedrelationships between the body length and body carbon contentof different species of Daphnia, which were collected from thehighly eutrophic Tjeukemeer, the Netherlands. From a seasonalsurvey of the carbon content of the daphnids. we concluded thatin Tjeukemeer D.galeata, D.galeata x cucullata and D.cucullataare food limited during the largest part of the year. Sincethe condition of the hybrids was relatively high as comparedwith the parental species when the food concentration was high,D.galeata x cucutlaia is expected to be the more successfultaxon during periods of high food availability. 相似文献
110.
Roohparvar R Huser A Zwiers LH De Waard MA 《Applied and environmental microbiology》2007,73(15):5011-5019
Medical drugs known to modulate the activity of human ATP-binding cassette (ABC) transporter proteins (modulators) were tested for the ability to potentiate the activity of the azole fungicide cyproconazole against in vitro growth of Mycosphaerella graminicola and to control disease development due to this pathogen on wheat seedlings. In vitro modulation of cyproconazole activity could be demonstrated in paper disk bioassays. Some of the active modulators (amitriptyline, flavanone, and phenothiazines) increased the accumulation of cyproconazole in M. graminicola, suggesting that they reversed cyproconazole efflux. However, synergism between cyproconazole and modulators against M. graminicola on wheat seedlings could not be shown. Despite their low in vitro toxicity to M. graminicola, some modulators (amitriptyline, loperamide, and promazine) did show significant intrinsic disease control activity in preventive and curative foliar spray tests with wheat seedlings. The results suggest that these compounds have indirect disease control activity based on modulation of fungal ABC transporters essential for virulence and constitute a new class of disease control agents. 相似文献