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21.
22.
Fredriksson Å Johansson Krogh E Hernebring M Pettersson E Javadi A Almstedt A Nyström T 《Aging cell》2012,11(4):634-643
In organisms with a soma-germ demarcation, the germline must be 'preserved' such that harmful damage is not transmitted to the offspring. Keeping the progeny free of damage may be achieved by gametes enjoying elevated, and/or more functional, homeostatic maintenance systems. This possibility was approached here by testing whether the soma and maturating oocytes (eggs) dissected from female Drosophila melanogaster in reproductive ages display differential capacities for protein quality control and whether these capacities change during aging and mating. Eggs exhibited a high capacity to prevent protein aggregation, strong capacity for 26S proteasome-dependent degradation and reduced levels of oxidatively damaged (carbonylated) proteins compared to the soma. The capacity to prevent protein aggregation was not affected in either soma or eggs by age and/or mating, while the 26S proteasome capacity declined in the soma but was maintained in the eggs of aged females. However, the levels of carbonylated proteins increased with age in both soma and eggs, and this increase was more pronounced in females allowed to mate continuously. Furthermore, the levels of carbonylated proteins in the eggs of mated flies correlated negatively with the propensity of the eggs to develop into an adult fly. In young flies, mating caused a decrease in 26S proteasome capacity and an increase in protein carbonylation in the soma, but not in the eggs. These results are in line with trade-off theories of aging where aging is considered a consequence of investment in reproduction over somatic maintenance. 相似文献
23.
Leishmaniasis worldwide and global estimates of its incidence 总被引:1,自引:0,他引:1
Alvar J Vélez ID Bern C Herrero M Desjeux P Cano J Jannin J den Boer M;WHO Leishmaniasis Control Team 《PloS one》2012,7(5):e35671
As part of a World Health Organization-led effort to update the empirical evidence base for the leishmaniases, national experts provided leishmaniasis case data for the last 5 years and information regarding treatment and control in their respective countries and a comprehensive literature review was conducted covering publications on leishmaniasis in 98 countries and three territories (see 'Leishmaniasis Country Profiles Text S1, S2, S3, S4, S5, S6, S7, S8, S9, S10, S11, S12, S13, S14, S15, S16, S17, S18, S19, S20, S21, S22, S23, S24, S25, S26, S27, S28, S29, S30, S31, S32, S33, S34, S35, S36, S37, S38, S39, S40, S41, S42, S43, S44, S45, S46, S47, S48, S49, S50, S51, S52, S53, S54, S55, S56, S57, S58, S59, S60, S61, S62, S63, S64, S65, S66, S67, S68, S69, S70, S71, S72, S73, S74, S75, S76, S77, S78, S79, S80, S81, S82, S83, S84, S85, S86, S87, S88, S89, S90, S91, S92, S93, S94, S95, S96, S97, S98, S99, S100, S101'). Additional information was collated during meetings conducted at WHO regional level between 2007 and 2011. Two questionnaires regarding epidemiology and drug access were completed by experts and national program managers. Visceral and cutaneous leishmaniasis incidence ranges were estimated by country and epidemiological region based on reported incidence, underreporting rates if available, and the judgment of national and international experts. Based on these estimates, approximately 0.2 to 0.4 cases and 0.7 to 1.2 million VL and CL cases, respectively, occur each year. More than 90% of global VL cases occur in six countries: India, Bangladesh, Sudan, South Sudan, Ethiopia and Brazil. Cutaneous leishmaniasis is more widely distributed, with about one-third of cases occurring in each of three epidemiological regions, the Americas, the Mediterranean basin, and western Asia from the Middle East to Central Asia. The ten countries with the highest estimated case counts, Afghanistan, Algeria, Colombia, Brazil, Iran, Syria, Ethiopia, North Sudan, Costa Rica and Peru, together account for 70 to 75% of global estimated CL incidence. Mortality data were extremely sparse and generally represent hospital-based deaths only. Using an overall case-fatality rate of 10%, we reach a tentative estimate of 20,000 to 40,000 leishmaniasis deaths per year. Although the information is very poor in a number of countries, this is the first in-depth exercise to better estimate the real impact of leishmaniasis. These data should help to define control strategies and reinforce leishmaniasis advocacy. 相似文献
24.
Alvar Carranza Camila de Mello Andrés Ligrone Silvana González Pablo Píriz Fabrizio Scarabino 《Biological invasions》2010,12(5):995-998
We report on the first sightings of the invasive Rapa Whelk Rapana venosa in Maldonado Bay (Punta del Este Harbor and Gorriti Island) using in vivo, underwater observations and video surveys. The
species was first detected in the Río de la Plata (Uruguay and Argentina) in 1999, and by 2004 it had extended its local distribution
to Punta del Este at the eastern boundary of the estuary. Observations performed by SCUBA diving showed that R. venosa is preying on native mussels Mytilus edulis and Brachidontes spp., and that formerly abundant mussel beds are being seriously depleted due to a combination of human extraction, habitat deterioration
and predation by the Rapa Whelk. 相似文献
25.
26.
Alvar D. Gossert Christelle Henry Marcel J. J. Blommers Wolfgang Jahnke César Fernández 《Journal of biomolecular NMR》2009,43(4):211-217
The identification of compounds that bind to a protein of interest is of central importance in contemporary drug research.
For screening of compound libraries, NMR techniques are widely used, in particular the Water-Ligand Observed via Gradient
SpectroscopY (WaterLOGSY) experiment. Here we present an optimized experiment, the polarization optimized WaterLOGSY (PO-WaterLOGSY).
Based on a water flip-back strategy in conjunction with model calculations and numerical simulations, the PO-WaterLOGSY is
optimized for water polarization recovery. Compared to a standard setup with the conventional WaterLOGSY, time consuming relaxation
delays have been considerably shortened and can even be omitted through this approach. Furthermore, the robustness of the
pulse sequence in an industrial setup was increased by the use of hard pulse trains for selective water excitation and water
suppression. The PO-WaterLOGSY thus yields increased time efficiency by factor of 3–5 when compared with previously published
schemes. These time savings have a substantial impact in drug discovery, since significantly larger compound libraries can
be tested in screening campaigns.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
27.
Hyaluronan oligosaccharides induce cell death through PI3-K/Akt pathway independently of NF-kappaB transcription factor 总被引:2,自引:0,他引:2
Alaniz L García MG Gallo-Rodriguez C Agusti R Sterín-Speziale N Hajos SE Alvarez E 《Glycobiology》2006,16(5):359-367
Several studies indicate that hyaluronan oligosaccharides (oHA) are able to modulate growth and cell survival in solid tumors; however, no studies have been undertaken to analyze the effect of oHA on T-lymphoid disorders. In this work we showed that oHA were able to induce apoptosis in lymphoma cell lines. Since PI3-K/Akt and nuclear factor-kappaB (NF-kappaB) are major factors involved in cell survival and anti-apoptotic pathways in lymphoma cells, we hypothesized that oHA could induce apoptosis through inhibition of these pathways. oHA were identified by a method which allows characterization of length using a high pH anion exchange chromatography with pulse amperometric detection (HPAEC-PAD). oHA inhibited PIP(3) production (principal product of PI3-K activity) and reduced Akt phosphorylation levels, similarly to the specific inhibitor wortmannin. However, treatment with either oHA or wortmannin failed to inhibit constitutive NF-kappaB activity and modulate IkappaBalpha protein levels, suggesting that PI3-K and NF-kappaB signaling pathways are not related in the cell lines used. Cell behavior differed using native hyaluronan (HA), which induced PIP(3) production, Akt phosphorylation, and NF-kappaB activation, although not related with cell survival since treatment with native HA showed no effect on apoptosis. Our results suggest that oHA induce apoptosis by suppression of PI3-K/Akt cell survival pathway without involving NF-kappaB activation, through a mechanism that differs from the one mediated by native HA. 相似文献
28.
Grönberg A Zettergren L Bergh K Ståhle M Heilborn J Angeby K Small PL Akuffo H Britton S 《PloS one》2010,5(11):e13839
Background
Mycobacterium ulcerans is the causative agent of necrotizing skin ulcerations in distinctive geographical areas. M. ulcerans produces a macrolide toxin, mycolactone, which has been identified as an important virulence factor in ulcer formation. Mycolactone is cytotoxic to fibroblasts and adipocytes in vitro and has modulating activity on immune cell functions. The effect of mycolactone on keratinocytes has not been reported previously and the mechanism of mycolactone toxicity is presently unknown. Many other macrolide substances have cytotoxic and immunosuppressive activities and mediate some of their effects via production of reactive oxygen species (ROS). We have studied the effect of mycolactone in vitro on human keratinocytes—key cells in wound healing—and tested the hypothesis that the cytotoxic effect of mycolactone is mediated by ROS.Methodology/Principal Findings
The effect of mycolactone on primary skin keratinocyte growth and cell numbers was investigated in serum free growth medium in the presence of different antioxidants. A concentration and time dependent reduction in keratinocyte cell numbers was observed after exposure to mycolactone. Several different antioxidants inhibited this effect partly. The ROS inhibiting substance deferoxamine, which acts via chelation of Fe2+, completely prevented mycolactone mediated cytotoxicity.Conclusions/Significance
This study demonstrates that mycolactone mediated cytotoxicity can be inhibited by deferoxamine, suggesting a role of iron and ROS in mycolactone induced cytotoxicity of keratinocytes. The data provide a basis for the understanding of Buruli ulcer pathology and the development of improved therapies for this disease. 相似文献29.
Jörg Menche Amitabh Sharma Michael H Cho Ruth J Mayer Stephen I Rennard Bartolome Celli Bruce E Miller Nick Locantore Ruth Tal-Singer Soumitra Ghosh Chris Larminie Glyn Bradley John H Riley Alvar Agusti Edwin K Silverman Albert-László Barabási 《BMC systems biology》2014,8(Z2):S8
Background
An important step toward understanding the biological mechanisms underlying a complex disease is a refined understanding of its clinical heterogeneity. Relating clinical and molecular differences may allow us to define more specific subtypes of patients that respond differently to therapeutic interventions.Results
We developed a novel unbiased method called diVIsive Shuffling Approach (VIStA) that identifies subgroups of patients by maximizing the difference in their gene expression patterns. We tested our algorithm on 140 subjects with Chronic Obstructive Pulmonary Disease (COPD) and found four distinct, biologically and clinically meaningful combinations of clinical characteristics that are associated with large gene expression differences. The dominant characteristic in these combinations was the severity of airflow limitation. Other frequently identified measures included emphysema, fibrinogen levels, phlegm, BMI and age. A pathway analysis of the differentially expressed genes in the identified subtypes suggests that VIStA is capable of capturing specific molecular signatures within in each group.Conclusions
The introduced methodology allowed us to identify combinations of clinical characteristics that correspond to clear gene expression differences. The resulting subtypes for COPD contribute to a better understanding of its heterogeneity.30.
Solène Grosdidier Antoni Ferrer Rosa Faner Janet Pi?ero Josep Roca Borja Cosío Alvar Agustí Joaquim Gea Ferran Sanz Laura I Furlong 《Respiratory research》2014,15(1)