80 research outputs found
Food matrix and isoflavones bioavailability in early post menopausal women: A European clinical study
The estrogenic effects of soy isoflavones (IF) on symptoms of menopause are of particular interest. The aim of the present study was to improve compliance of IF in two IF-enriched foods providing the same IF circulating levels in postmenopausal women. Forty-two healthy postmenopausal women (mean age: 53.28 years) were recruited for a randomized, crossover, multicenter trial conducted in the Netherlands, Italy and France. Over 18 days, volunteers were assigned to two groups and supplemented with two different IF-enriched foods (100 mg IF aglycones/two servings). The first group had to eat two biscuits daily for three days. After a wash-out period (11 d), they received cereal bars for three days. The second group started with the cereal bars and finished with biscuits. After IF intake, plasma and urinary levels of genistein, daidzein, O desmethyl angolensin and equol significantly increased and returned to baseline level after the washout period. There was no difference between biscuits and cereals bars intake, as shown by group values at each end of experimental period (day 4 or day 18). Both matrixes are comparable in terms of IF-circulating levels and could be used independently
Species Composition and Diversity in two Selected Lowland Tropical Rainforests in Sri Lanka and their Relationships to Temperature and Precipitation
Tropical rainforests are characterised by high species diversity, which may be due to a range of factors such as climate, topography, soil properties and the level of disturbance, both natural and anthropogenic. This study focused on investigating the species composition, richness, diversity and their conservation status in lowland tropical rainforests at two selected locations in Sri Lanka and determining their relationships to temperature and precipitation. Two permanent one-hectare sampling plots each were established at the Kanneliya (KDN1 and KDN2) and Pitadeniya-Sinharaja (PTD1 and PTD2) Forest Reserves. All trees with dbh≥10 cm were enumerated. A total of 3,303 trees were recorded, representing 158 species from 91 genera and 53 families, with a total basal area of 196.26 m2. Most abundant plant species were Alstonia macrophylla in KDN1 (11.7% of trees with dbh≥10 cm), Syzygium grande in KDN2 (9.8%), Shorea affinis in PTD1 (15.8%) Mesua thwaitesii in PTD2 (17.5%). Cullenia rosayroana (7.2%) is the most abundant species within the whole study area. While 25 species were recorded in all four plots, 70 species were found in only one location. Genus Shorea (18.6%) is the most common including 12 different species and Dipterocarpaceae (21.9%) is the most common family including 19 species. KDN1 recorded 1,011 plants from 108 species, with 74.3% endemic, 12.8% native and 11.9% exotic species. Other study sites recorded only endemic (88% at KDN2, 83.7% at PTD1 and 82.3% at PTD2) and native species. In comparison to PTD, KDN recorded higher numbers of trees with dbh≥10 cm (Chi-square p<0.0001), species (p<0.0001) and genera (p=0.0091). KDN also recorded a higher number of families but the difference was not significant (p=0.358). All indices of species diversity (Shannon index, H and Simpson index, D), evenness (J) and richness (R) are higher at KDN. However, only the difference in D was statistically-significant at p=0.05. Multiple regression analysis using the stepwise procedure showed that the number of trees with dbh≥10 cm and the species number increased with increasing average annual air temperature (T) but decreased with annual total precipitation (P). On the other hand, the numbers of genera and families increased with decreasing P with T not having a significant influence. The two diversity indices, H and D, increased with decreasing P and increasing T. In contrast, increasing P decreased J and R whereas variation in T did not have a significant influence. These findings provide important insights in to dynamics plant diversity in response to environmental changes.Keywords: Species composition, Species diversity, Tropical rainforest
Assessment of tsunami damage on the .coastal vegetation in five selected districts in the coastal zone of Sri Lanka, after one and half years of tsunami
Tsunami, the ki lIer wave swept nearly two thirds of the coast of Sri Lanka on 26lh of December, 2004.About 40,000 people died and around 500,000 people were displaced, more than 119,000 housesdamaged either fully or partially. About 13 coastal districts were directly affected, the north and eastsuffered the brunt of the blow accounting for about 2/3 of deaths and 60% of displacements. In termsof ecological aspects, with the exception of few species, most of the vegetation suffered total orpartial death, lagoons, estuaries, coral reefs, sea grass beds, salt marshes and mangroves experiencedthe damage at varying levels. Th is study was conducted with the patronage of the Food and AgriculturalOrganisation of the UN to scientifically assess the response of the coastal ecosystems with specialreference to coastal forests to the Tsunami, almost one and half years of the incident.The study focused on 5 tsunami affected districts namely, Kalutara, Galle, Matara, Hambantota andArnpara. In each district, approximately 6 sampling locations selected based on the topography mapsand ground information. In each sampling location, a transect which was 10m wide and upto 250minland was taken. The transect was divided into 50m blocks, the first one laid at the start of vegetationline of the beach. In each 50m section of the transect, all the plant species were enumerated. For theground vegetation, percentage ground cover was taken. Using an index, the level of damage wasevaluated for each plant. Composite soil samples were taken at each 50m segment and analysed forElectrical Conductivity, Soil Organic Carbon and major nutrients. Water samples were taken fromexisting wells located close by.Although most of the vegetation, except for few exceptions, suffered badly at the time of Tsunami,there was extensive regeneration on the coast at the time of our study. The species which sufferedthe tsunami damage most were Palmyrah palm (Borassus flab ellifer), Del (Artocarplls nobilis),Araliya tBorassus flabellifer), Puwak (Areca catechu), Banana (Musa sppv; Kitul (Caryota urens),Guava (Psidium guajava), Avacardo pears (Persea gratissimai, trees of Citrus family ie Oranges,Lemon, Lime (Citrus spp.) Alstonia, Teak (Tectona grandis) etc. Of these, most of the species hadregenerated to varying degrees, the most difficult ones being Araliya, Palmyrah, plants of citrus family,Kitul, Guava.With a view to find out the species which are more robust in the regeneration, percentage groundcover (in ground vegetation) and relative abundance (in tree/shrub vegetation) were taken in each 50m segment of a plot. The districts did not vary significantly in the biodiversity. However, the speciesabundance showed a significant variation especially between the districts ofthe western coast (Kalutara,Galle, Matara) with that of south and eastern coasts (Hambantota and Ampara). While Mudu bimthamburu (Ipomea pescaprae) was the most prominent ground cover in the western districts, Maharavana ravul (Spinifex spp.) was more prominent in both south and eastern districts. With regard tothe abundance of trees/shrubs, Wetakeiyya (Pandanus spi, Coconuts (Cocos nuciferai, Gam suriya(Thespesia spp.y, Mudilla (Barringtonia spp.i, Domba were most abundant. In the South and Easterndistricts, Maliththan (Woodfordiafruitocosa), Andara (Prosopisjuliflora), Palmyrah palm, Cashwnut (Anacardium occidentale) and Neem iAzadirachta indica), Indi, (Phoenix spp) Korakaha/Kayan (Memecylon angustifoliumi were prominent. In the South and South-eastern districts, Aththana(Datura mete/), Wal kochchi had spread into invasive levels while the regeneration of Ranawara(Cassia auriculata) also had increased.With regard to the physical parameters, soil carbon content showed a decrease with the increase indistance from the beach. The Electrical Conductivity (EC) also showed a decreasing trend with theincreasing distance from the beach in all the districts studied. In general, all the nutrients (Total N,Available P, Available K, Ca, Mg and Na) showed an increase upto about 50m compared to that ofnon tsunami levels and then decreased. The pH of the water samples taken in all the districts werebetween 7-8 indicating a neutral level while the EC values were higher than the standard of 4 milsemens.With regard to the establishment of Green Belt, the coastal area could be broadly categorised intonatural, rural and urban landscapes. For the natural landscapes like mangroves, sand dunes and coastalforests, facilitation/restoration of the natural vegetation is recommended. Selection of species shouldbe in line with the naturally occurring ones in the ecosystem. In total locations, planting a strip ofnatural littoral woodland and strand plants seaward of agricultural crops is suitable. For urban locations,patches of natural vegetation could be integrated as far as possible with the most suitable concept forthe area. There could be open grassed/sandy/paved parks or playgrounds or sports grounds of varioussizes, provided there is a substantial belt of trees on the seaward side, and in cyclone prone areas,wind shelter belts on all sides. In cyclone prone areas, wind shelter belts should be planted aroundcrops and settlements: the trees and shrubs used could be introduced species as well as indigenous/native (found naturally in Sri Lanka) and endemic (found naturally only in Sri Lanka) species.The design of the Green belt should inc lude both ground vegetation, shrubs and then trees. Based onthe study results, composition of the vegetation for both ground vegetation, shrub layer and the treelayer has been proposed for all the 5 districts. In the tree layer, there were two distinctions, one for thebioshield which is located at close proximity to the sea and then the trees outside the bioshield comprisingof more multipurpose ones serving both protection and production purposes. Further, general designswere recommended for the west coast and southeast and eastern coasts. Guidelines were also proposedfor rehabilitation of the mangrove areas and sand dunes.
Evaluation of envelope domain III-based single chimeric tetravalent antigen and monovalent antigen mixtures for the detection of anti-dengue antibodies in human sera
<p>Abstract</p> <p>Background</p> <p>Flavivirus cross-reactive antibodies in human sera interfere with the definitive identification of dengue virus (DENV) infections especially in areas with multiple co-circulating flaviviruses. Use of DENV envelope domain-III (EDIII) can partially resolve the problem. This study has examined the effect of (i) incorporating the EDIIIs of four DENV serotypes into a single chimeric antigen, and (ii) immobilizing the antigen through specific interaction on the sensitivity and specificity of anti-DENV antibody detection.</p> <p>Methods</p> <p>A sera panel (n = 164) was assembled and characterized using commercial kits for infection by DENV and a host of other pathogens. Anti-DENV antibodies of both IgM and IgG classes in this panel were detected in indirect ELISAs using a mixture of monovalent EDIIIs, a chimeric EDIII-based tetravalent antigen, EDIII-T, and a biotinylated version of the latter as coating antigens. The sensitivity and specificity of these assays were compared to those obtained using the PanBio Dengue IgG/IgM ELISAs.</p> <p>Results</p> <p>The performance of dengue IgG and IgM indirect ELISAs, using either a physical mixture of four EDIIIs or the single chimeric EDIII-T antigen, were comparable. Coating of a biotinylated version of the tetravalent antigen on streptavidin plates enhanced sensitivity without compromising specificity.</p> <p>Conclusions</p> <p>The incorporation of the EDIIIs of the four DENV serotypes into a single chimeric antigen did not adversely affect assay outcome in indirect ELISAs. Oriented, rather than random, immobilization of the tetravalent antigen enhanced sensitivity of detection of anti-DENV antibodies with retention of 100% specificity.</p
An assessment of vegetation and canopy structure of moderately exploited natural forest area in Yagirala forest reserve
Study assessed the vegetation composition and structure and the forest canopy structure in terms ofLeaf Area Index (LAI), Mean Leaf Angle (MLA) and canopy openness in different elevationalclasses of moderately exploited natural forest area which covers about 82% of total natural forestcover in Yagirala forest reserve, a tropical lowland rain forest selectively logged by State TimberCooperation in late 70's.Canopy architecture termed as angle distribution of foliage elements (Chen et al. 1992), can bequantified by the leaf area index (LAI) and mean leaf angle (MLA). In this study Hemisphericalphotographic method was used to characterize canopy architecture at three elevational classes (i.e.valley, mid-slope and ridge top). At each elevational class, hemispherical photos ofthe forest canopywere taken at each sampling point at a height of l m above the ground along transects up to 200m at50m intervals. Hemispherical photographs were analyzed using Hemiview 2.1 canopy analysis softwareA vegetation survey was carried out to determine floristic composition of dam inant species and fam i!ies,which contribute more to the forest canopy. The enumeration was carried out using 0.05 ha circularplots at three elevational classes, totally covering 0.6ha of the area. Individuals taller 1m were enumeratedand species, diameter at breast height (dbh) and total height measurements were recorded and relativebasal area, relative frequency, relative density and Importance Value Index (IVI), diameter classdistribution were estimated.Leaf area index (LAI) and mean leaf angle (MLA) did not show significant variation between threeelevational classes. LAlmean value of low elevation areas show high value of2.256 and mean valueof high elevation areas show low value of 2.087. Average MLA value for the moderately exploitedarea is 29.14. Canopy openness given in terms of visual sky fraction is also not significantly diferentbetween three elevational classes. The results give an estimation of homogeneity of canopy opennesswithin the moderately exproited natural forest.
Circulation of Different Lineages of Dengue Virus 2, Genotype American/Asian in Brazil: Dynamics and Molecular and Phylogenetic Characterization
The American/Asian genotype of Dengue virus type 2 (DENV-2) was introduced into the Americas in the 80′s. Although there is no data showing when this genotype was first introduced into Brazil, it was first detected in Brazil in 1990. After which the virus spread throughout the country and major epidemics occurred in 1998, 2007/08 and 2010. In this study we sequenced 12 DENV-2 genomes obtained from serum samples of patients with dengue fever residing in São José do Rio Preto, São Paulo (SJRP/SP), Brazil, in 2008. The whole open reading frame or envelope sequences were used to perform phylogenetic, phylogeographic and evolutionary analyses. Isolates from SJRP/SP were grouped within one lineage (BR3) close to isolates from Rio de Janeiro, Brazil. Isolates from SJRP were probably introduced there at least in 2007, prior to its detection in the 2008 outbreak. DENV-2 circulation in Brazil is characterized by the introduction, displacement and circulation of three well-defined lineages in different times, most probably from the Caribbean. Thirty-seven unique amino acid substitutions were observed among the lineages, including seven amino acid differences in domains I to III of the envelope protein. Moreover, we dated here, for the first time, the introduction of American/Asian genotype into Brazil (lineage BR1) to 1988/89, followed by the introduction of lineages BR2 (1998–2000) and BR3 (2003–05). Our results show a delay between the introduction and detection of DENV-2 lineages in Brazil, reinforcing the importance and need for surveillance programs to detect and trace the evolution of these viruses. Additionally, Brazilian DENV-2 differed in genetic diversity, date of introduction and geographic origin and distribution in Brazil, and these are important factors for the evolution, dynamics and control of dengue.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq Grant )Fundação de Amparo à Pesquisa do Estado de São PauloFundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG grant
DNA Vaccines against Dengue Virus Type 2 Based on Truncate Envelope Protein or Its Domain III
Two DNA vaccines were constructed encoding the ectodomain (domains I, II and III) of the DENV2 envelope protein (pE1D2) or only its domain III (pE2D2), fused to the human tissue plasminogen activator signal peptide (t-PA). The expression and secretion of recombinant proteins was confirmed in vitro in BHK cells transfected with the two plasmids, detected by immunofluorescence or immunoprecipitation of metabolically labeled gene products, using polyclonal and monoclonal antibodies against DENV2. Besides, results reveal that the ectodomain of the E protein can be efficiently expressed in vivo, in a mammalian system, without the prM protein that is hypothesized to act as a chaperonin during dengue infection. Balb/c mice were immunized with the DNA vaccines and challenged with a lethal dose of DENV2. All pE1D2-vaccinated mice survived challenge, while 45% of animals immunized with the pE2D2 died after infection. Furthermore, only 10% of pE1D2-immunized mice presented some clinical signs of infection after challenge, whereas most of animals inoculated with the pE2D2 showed effects of the disease with high morbidity degrees. Levels of neutralizing antibodies were significantly higher in pE1D2-vaccinated mice than in pE2D2-immunized animals, also suggesting that the pE1D2 vaccine was more protective than the pE2D2
Dengue virus neutralizing antibody levels associated with protection from infection in Thai cluster studies
BACKGROUND: Long-term homologous and temporary heterologous protection from dengue virus (DENV) infection may be mediated by neutralizing antibodies. However, neutralizing antibody titers (NTs) have not been clearly associated with protection from infection.
METHODOLOGY/PRINCIPAL FINDINGS: Data from two geographic cluster studies conducted in Kamphaeng Phet, Thailand were used for this analysis. In the first study (2004-2007), cluster investigations of 100-meter radius were triggered by DENV-infected index cases from a concurrent prospective cohort. Subjects between 6 months and 15 years old were evaluated for DENV infection at days 0 and 15 by DENV PCR and IgM ELISA. In the second study (2009-2012), clusters of 200-meter radius were triggered by DENV-infected index cases admitted to the provincial hospital. Subjects of any age 6 months and older were evaluated for DENV infection at days 0 and 14. In both studies, subjects who were DENV PCR positive at day 14/15 were considered to have been susceptible on day 0. Comparison subjects from houses in which someone had documented DENV infection, but the subject remained DENV negative at days 0 and 14/15, were considered non-susceptible. Day 0 samples were presumed to be from just before virus exposure, and underwent plaque reduction neutralization testing (PRNT). Seventeen susceptible (six DENV-1, five DENV-2, and six DENV-4), and 32 non-susceptible (13 exposed to DENV-1, 10 DENV-2, and 9 DENV-4) subjects were evaluated. Comparing subjects exposed to the same serotype, receiver operating characteristic (ROC) curves identified homotypic PRNT titers of 11, 323 and 16 for DENV-1, -2 and -4, respectively, to differentiate susceptible from non-susceptible subjects.
CONCLUSIONS/SIGNIFICANCE: PRNT titers were associated with protection from infection by DENV-1, -2 and -4. Protective NTs appeared to be serotype-dependent and may be higher for DENV-2 than other serotypes. These findings are relevant for both dengue epidemiology studies and vaccine development efforts
Endemic Dengue Associated with the Co-Circulation of Multiple Viral Lineages and Localized Density-Dependent Transmission
Dengue is one of the most important infectious diseases of humans and has spread throughout much of the tropical and subtropical world. Despite this widespread dispersal, the determinants of dengue transmission in endemic populations are not well understood, although essential for virus control. To address this issue we performed a phylogeographic analysis of 751 complete genome sequences of dengue 1 virus (DENV-1) sampled from both rural (Dong Thap) and urban (Ho Chi Minh City) populations in southern Viet Nam during the period 2003–2008. We show that DENV-1 in Viet Nam exhibits strong spatial clustering, with likely importation from Cambodia on multiple occasions. Notably, multiple lineages of DENV-1 co-circulated in Ho Chi Minh City. That these lineages emerged at approximately the same time and dispersed over similar spatial regions suggests that they are of broadly equivalent fitness. We also observed an important relationship between the density of the human host population and the dispersion rate of dengue, such that DENV-1 tends to move from urban to rural populations, and that densely populated regions within Ho Chi Minh City act as major transmission foci. Despite these fluid dynamics, the dispersion rates of DENV-1 are relatively low, particularly in Ho Chi Minh City where the virus moves less than an average of 20 km/year. These low rates suggest a major role for mosquito-mediated dispersal, such that DENV-1 does not need to move great distances to infect a new host when there are abundant susceptibles, and imply that control measures should be directed toward the most densely populated urban environments
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