897 resultados para Screening and identification of vibrios


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In this report we disclose the synthesis, vasodilatory activity, and identification of bioactive conformation of new N-acylhydrazone and N-methyl-N-acylhydrazone derivatives, structurally designed by bioisosteric replacements of previously described cardioactive compounds LASSBio-294 and its N-methyl derivative LASSBio-785. Some of these novel derivatives presented improved vasorelaxant properties, being new cardiovascular drug candidates. (C) 2009 Elsevier Masson SAS. All rights reserved.

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This paper reports the separation and identification of indole alkaloids, steroids and triterpenoids from the ethanolic extracts of Tabernaemontana hilariana (Apocynaceae). The alkaloidal fractions from the ethanolic extracts obtained (root barks, green fruits, ripe fruits and seeds) were fractionated and analysed by thin-layer chromatography, capillary gas chromatography-flame ionization detection (cGC-FID) as well as by high-resolution gas chromatography-mass spectrometry (HRGC-MS). 3-Hydroxycoronaridine, ibogamine, coronaridine pseudoindoxyl, coronaridine, catharanthine, voacangine hydroxyindolenine, voacangine pseudoindoxyl, tabernanthine, tetraphyllicine, 3-hydroxyvoacangine, voacangine, isovoacangine and 3-oxocoronaridine were identified. The insoluble fraction of ethanolic extracts obtained from the root barks and green fruits were analysed and ten aliphatic constituents were also identified by cGC-FID and HRGC-MS. (C) 1998 Elsevier B.V. B.V. All rights reserved.

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Drug delivery systems involving the use of polymers are widely studied and discovery of biocompatible polymers has become the focus of research in this area. Psoralen loaded poly(DL-lactide-co-glycolide) (PLGA) microspheres to be used in PUVA therapy (psoralen and UVA irradiation (ultraviolet A, 320-400 nm) of psoriasis were identified in paraffin sections by histological analysis. The psoralen loaded PLGA microspheres were prepared using the solvent evaporation technique. They were spherical and possessed an external smooth surface as observed by scanning electron microscopy (SEM) analysis. This study describes a modification in the routine preparation of microsphere samples for examination by light microscopy. The changes involved fixative agents and/or stains allowing the identification of microspheres containing a non-fluorescent material. The preservation and identification of microspheres in tissues for histological processing in paraffin was greatly improved by these modifications as proven by our results. (c) 2007 Elsevicr Ltd. All rights reserved.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Consolidation of international guidelines for the management of canine populations in urban areas and proposal of performance indicators The objective of this study is to propose a generic program for the management of urban canine populations with suggestion of performance indicators. The following international guidelines on canine population management were revised and consolidated: World Health Organization, World Organisation for Animal Health, World Society for the Protection of Animals, International Companion Animal Management Coalition, and the Food and Agriculture Organization. Management programs should cover: situation diagnosis, including estimates of population size; social participation with involvement of various sectors in the planning and execution of strategies; educational actions to promote humane values, animal welfare, community health, and responsible ownership (through purchase or adoption); environmental and waste management to eliminate sources of food and shelter; registration and identification of animals; animal health care, reproductive control; prevention and control of zoonoses; control of animal commerce; management of animal behavior and adequate solutions for abandoned animals; and laws regulating responsible ownership, prevention of abandonment and zoonoses. To monitor these actions, four groups of indicators are suggested: animal population indicators, human/animal interaction indicators, public service indicators, and zoonosis indicators. The management of stray canine populations requires political, sanitary, ethologic, ecologic, and humanitarian strategies that are socially acceptable and environmentally sustainable. Such measures must also include the control of zoonoses such as rabies and leishmaniasis, considering the concept of "one health," which benefits both the animals and people in the community.

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OBJECTIVE: To determine the impact of a community based Helicobacter pylori screening and eradication programme on the incidence of dyspepsia, resource use, and quality of life, including a cost consequences analysis. DESIGN: H pylori screening programme followed by randomised placebo controlled trial of eradication. SETTING: Seven general practices in southwest England. PARTICIPANTS: 10,537 unselected people aged 20-59 years were screened for H pylori infection (13C urea breath test); 1558 of the 1636 participants who tested positive were randomised to H pylori eradication treatment or placebo, and 1539 (99%) were followed up for two years. INTERVENTION: Ranitidine bismuth citrate 400 mg and clarithromycin 500 mg twice daily for two weeks or placebo. MAIN OUTCOME MEASURES: Primary care consultation rates for dyspepsia (defined as epigastric pain) two years after randomisation, with secondary outcomes of dyspepsia symptoms, resource use, NHS costs, and quality of life. RESULTS: In the eradication group, 35% fewer participants consulted for dyspepsia over two years compared with the placebo group (55/787 v 78/771; odds ratio 0.65, 95% confidence interval 0.46 to 0.94; P = 0.021; number needed to treat 30) and 29% fewer participants had regular symptoms (odds ratio 0.71, 0.56 to 0.90; P = 0.05). NHS costs were 84.70 pounds sterling (74.90 pounds sterling to 93.91 pounds sterling) greater per participant in the eradication group over two years, of which 83.40 pounds sterling (146 dollars; 121 euro) was the cost of eradication treatment. No difference in quality of life existed between the two groups. CONCLUSIONS: Community screening and eradication of H pylori is feasible in the general population and led to significant reductions in the number of people who consulted for dyspepsia and had symptoms two years after treatment. These benefits have to be balanced against the costs of eradication treatment, so a targeted eradication strategy in dyspeptic patients may be preferable.

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The goal of this research is to provide a framework for vibro-acoustical analysis and design of a multiple-layer constrained damping structure. The existing research on damping and viscoelastic damping mechanism is limited to the following four mainstream approaches: modeling techniques of damping treatments/materials; control through the electrical-mechanical effect using the piezoelectric layer; optimization by adjusting the parameters of the structure to meet the design requirements; and identification of the damping material’s properties through the response of the structure. This research proposes a systematic design methodology for the multiple-layer constrained damping beam giving consideration to vibro-acoustics. A modeling technique to study the vibro-acoustics of multiple-layered viscoelastic laminated beams using the Biot damping model is presented using a hybrid numerical model. The boundary element method (BEM) is used to model the acoustical cavity whereas the Finite Element Method (FEM) is the basis for vibration analysis of the multiple-layered beam structure. Through the proposed procedure, the analysis can easily be extended to other complex geometry with arbitrary boundary conditions. The nonlinear behavior of viscoelastic damping materials is represented by the Biot damping model taking into account the effects of frequency, temperature and different damping materials for individual layers. A curve-fitting procedure used to obtain the Biot constants for different damping materials for each temperature is explained. The results from structural vibration analysis for selected beams agree with published closed-form results and results for the radiated noise for a sample beam structure obtained using a commercial BEM software is compared with the acoustical results of the same beam with using the Biot damping model. The extension of the Biot damping model is demonstrated to study MDOF (Multiple Degrees of Freedom) dynamics equations of a discrete system in order to introduce different types of viscoelastic damping materials. The mechanical properties of viscoelastic damping materials such as shear modulus and loss factor change with respect to different ambient temperatures and frequencies. The application of multiple-layer treatment increases the damping characteristic of the structure significantly and thus helps to attenuate the vibration and noise for a broad range of frequency and temperature. The main contributions of this dissertation include the following three major tasks: 1) Study of the viscoelastic damping mechanism and the dynamics equation of a multilayer damped system incorporating the Biot damping model. 2) Building the Finite Element Method (FEM) model of the multiple-layer constrained viscoelastic damping beam and conducting the vibration analysis. 3) Extending the vibration problem to the Boundary Element Method (BEM) based acoustical problem and comparing the results with commercial simulation software.

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Hardwoods comprise about half of the biomass of forestlands in North America and present many uses including economic, ecological and aesthetic functions. Forest trees rely on the genetic variation within tree populations to overcome the many biotic, abiotic, anthropogenic factors which are further worsened by climate change, that threaten their continued survival and functionality. To harness these inherent genetic variations of tree populations, informed knowledge of the genomic resources and techniques, which are currently lacking or very limited, are imperative for forest managers. The current study therefore aimed to develop genomic microsatellite markers for the leguminous tree species, honey locust, Gleditsia triacanthos L. and test their applicability in assessing genetic variation, estimation of gene flow patterns and identification of a full-sib mapping population. We also aimed to test the usefulness of already developed nuclear and gene-based microsatellite markers in delineation of species and taxonomic relationships between four of the taxonomically difficult Section Lobatae species (Quercus coccinea, Q. ellipsoidalis, Q. rubra and Q. velutina. We recorded 100% amplification of G. triacanthos genomic microsatellites developed using Illumina sequencing techniques in a panel of seven unrelated individuals with 14 of these showing high polymorphism and reproducibility. When characterized in 36 natural population samples, we recorded 20 alleles per locus with no indication for null alleles at 13 of the 14 microsatellites. This is the first report of genomic microsatellites for this species. Honey locust trees occur in fragmented populations of abandoned farmlands and pastures and is described as essentially dioecious. Pollen dispersal if the main source of gene flow within and between populations with the ability to offset the effects of random genetic drift. Factors known to influence gene include fragmentation and degree of isolation, which make the patterns gene flow in fragmented populations of honey locust a necessity for their sustainable management. In this follow-up study, we used a subset of nine of the 14 developed gSSRs to estimate gene flow and identify a full-sib mapping population in two isolated fragments of honey locust. Our analyses indicated that the majority of the seedlings (65-100% - at both strict and relaxed assignment thresholds) were sired by pollen from outside the two fragment populations. Only one selfing event was recorded confirming the functional dioeciousness of honey locust and that the seed parents are almost completely outcrossed. From the Butternut Valley, TN population, pollen donor genotypes were reconstructed and used in paternity assignment analyses to identify a relatively large full-sib family comprised of 149 individuals, proving the usefulness of isolated forest fragments in identification of full-sib families. In the Ames Plantation stand, contemporary pollen dispersal followed a fat-tailed exponential-power distribution, an indication of effective gene flow. Our estimate of δ was 4,282.28 m, suggesting that insect pollinators of honey locust disperse pollen over very long distances. The high proportion of pollen influx into our sampled population implies that our fragment population forms part of a large effectively reproducing population. The high tendency of oak species to hybridize while still maintaining their species identity make it difficult to resolve their taxonomic relationships. Oaks of the section Lobatae are famous in this regard and remain unresolved at both morphological and genetic markers. We applied 28 microsatellite markers including outlier loci with potential roles in reproductive isolation and adaptive divergence between species to natural populations of four known interfertile red oaks, Q. coccinea, Q. ellpsoidalis, Q. rubra and Q. velutina. To better resolve the taxonomic relationships in this difficult clade, we assigned individual samples to species, identified hybrids and introgressive forms and reconstructed phylogenetic relationships among the four species after exclusion of genetically intermediate individuals. Genetic assignment analyses identified four distinct species clusters, with Q. rubra most differentiated from the three other species, but also with a comparatively large number of misclassified individuals (7.14%), hybrids (7.14%) and introgressive forms (18.83%) between Q. ellipsoidalis and Q. velutina. After the exclusion of genetically intermediate individuals, Q. ellipsoidalis grouped as sister species to the largely parapatric Q. coccinea with high bootstrap support (91 %). Genetically intermediate forms in a mixed species stand were located proximate to both potential parental species, which supports recent hybridization of Q. velutina with both Q. ellipsoidalis and Q. rubra. Analyses of genome-wide patterns of interspecific differentiation can provide a better understanding of speciation processes and taxonomic relationships in this taxonomically difficult group of red oak species.

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Quantification of the volumes of sediment removed by rock–slope failure and debris flows and identification of their coupling and controls are pertinent to understanding mountain basin sediment yield and landscape evolution. This study captures a multi-decadal period of hillslope erosion and channel change following an extreme rock avalanche in 1961 in the Illgraben, a catchment prone to debris flows in the Swiss Alps. We analyzed photogrammetrically-derived datasets of hillslope and channel erosion and deposition along with climatic and seismic variables for a 43 year period from 1963 to 2005. Based on these analyses we identify and discuss (1) patterns of hillslope production, channel transfer and catchment sediment yield, (2) their dominant interactions with climatic and seismic variables, and (3) the nature of hillslope–channel coupling and implications for sediment yield and landscape evolution in this mountain basin. Our results show an increase in the mean hillslope erosion rate in the 1980s from 0.24 ± 0.01 m yr− 1 to 0.42 ± 0.03 m yr− 1 that coincided with a significant increase in air temperature and decrease in snow cover depth and duration, which we presume led to an increase in the exposure of the slopes to thermal weathering processes. The combination of highly fractured slopes close to the threshold angle for failure, and multiple potential triggering mechanisms, means that it is difficult to identify an individual control on slope failure. On the other hand, the rate of channel change was strongly related to variables influencing runoff. A period of particularly high channel erosion rate of 0.74 ± 0.02 m yr− 1 (1992–1998) coincided with an increase in the frequency and magnitude of intense rainfall events. Hillslope erosion exceeded channel erosion on average, indicative of a downslope-directed coupling relationship between hillslope and channel, and demonstrating the first order control of rock–slope failure on catchment sediment yield and landscape evolution.

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The synapses in the cerebral cortex can be classified into two main types, Gray’s type I and type II, which correspond to asymmetric (mostly glutamatergic excitatory) and symmetric (inhibitory GABAergic) synapses, respectively. Hence, the quantification and identification of their different types and the proportions in which they are found, is extraordinarily important in terms of brain function. The ideal approach to calculate the number of synapses per unit volume is to analyze 3D samples reconstructed from serial sections. However, obtaining serial sections by transmission electron microscopy is an extremely time consuming and technically demanding task. Using focused ion beam/scanning electron microscope microscopy, we recently showed that virtually all synapses can be accurately identified as asymmetric or symmetric synapses when they are visualized, reconstructed, and quantified from large 3D tissue samples obtained in an automated manner. Nevertheless, the analysis, segmentation, and quantification of synapses is still a labor intensive procedure. Thus, novel solutions are currently necessary to deal with the large volume of data that is being generated by automated 3D electron microscopy. Accordingly, we have developed ESPINA, a software tool that performs the automated segmentation and counting of synapses in a reconstructed 3D volume of the cerebral cortex, and that greatly facilitates and accelerates these processes.

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We had earlier identified the pcnB locus as the gene for the major Escherichia coli poly(A) polymerase (PAP I). In this report, we describe the disruption and identification of a candidate gene for a second poly(A) polymerase (PAP II) by an experimental strategy which was based on the assumption that the viability of E. coli depends on the presence of either PAP I or PAP II. The coding region thus identified is the open reading frame f310, located at about 87 min on the E. coli chromosome. The following lines of evidence support f310 as the gene for PAP II: (i) the deduced peptide encoded by f310 has a molecular weight of 36,300, similar to the molecular weight of 35,000 estimated by gel filtration of PAP II; (ii) the deduced f310 product is a relatively hydrophobic polypeptide with a pI of 9.4, consistent with the properties of partially purified PAP II; (iii) overexpression of f310 leads to the formation of inclusion bodies whose solubilization and renaturation yields poly(A) polymerase activity that corresponds to a 35-kDa protein as shown by enzyme blotting; and (iv) expression of a f310 fusion construct with hexahistidine at the N-terminus of the coding region allowed purification of a poly(A) polymerase fraction whose major component is a 36-kDa protein. E. coli PAP II has no significant sequence homology either to PAP I or to the viral and eukaryotic poly(A) polymerases, suggesting that the bacterial poly(A) polymerases have evolved independently. An interesting feature of the PAP II sequence is the presence of sets of two paired cysteine and histidine residues that resemble the RNA binding motifs seen in some other proteins.

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To isolate and characterize effector molecules of the transforming growth factor beta (TGFbeta) signaling pathway we have used a genetic approach involving the generation of stable recessive mutants, defective in their TGFbeta signaling, which can subsequently be functionally complemented to clone the affected genes. We have generated a cell line derived from a hypoxanthine-guanine phosphoribosyltransferase negative (HPRT-) HT1080 clone that contains the selectable marker Escherichia coli guanine phosphoribosyltransferase (gpt) linked to a TGFbeta-responsive promoter. This cell line proliferates or dies in the appropriate selection medium in response to TGFbeta. We have isolated three distinct TGFbeta-unresponsive mutants following chemical mutagenesis. Somatic cell hybrids between pairs of individual TGFbeta-unresponsive clones reveal that each is in a distinct complementation group. Each mutant clone retains all three TGFbeta receptors yet fails to induce a TGFbeta-inducible luciferase reporter construct or TGFbeta-mediated plasminogen activator inhibitor-1 (PAI-1) expression. Two of the three have an attenuated TGFbeta-induced fibronectin response, whereas in the other mutant the fibronectin response is intact. These TGFbeta-unresponsive cells should allow selection and identification of signaling molecules through functional complementation.

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The fate of vitamin E and the formation and identification of its transformation products were investigated at different stages of the manufacturing process of commercially produced cross-linked (by γ-irradiation) UHMWPE stabilised with vitamin E (vitamin E infused-post irradiation) used for tibia-components (as articulating surfaces) in total knee arthroplasty (total knee replacement). Vitamin E (α-tocopherol) and its transformation products were extracted from microtomed Tibia films and the different products were separated, isolated, purified using high performance liquid chromatography (HPLC), and characterised by spectroscopic methods and LC-MS. The amount of vitamin E and that of the products formed in the different Tibia samples and in their extracts were also quantified using FTIR and HPLC analysis and calibration curves. Thorough analysis of the Tibia extracts has shown that a number of vitamin E transformation products were formed at different concentrations at two selected stages of the implant manufacturing process that is before and after sterilisation by γ-irradiation. The identified products were found to correspond mainly to different stereoisomeric forms of a small number of vitamin E transformation products. Most of the observed products were of dimeric and trimeric nature with their identity confirmed through a detailed study of their spectral and chromatographic characteristics. It was found that the products of vitamin E, prior to the sterilisation step but after the crosslinking and doping of vitamin E, were mainly the dihydroxydimers and trimers (Tibia samples at this stage are referred to as “Tibia-VEPE”). After sterilisation and completion of the manufacturing process, additional dimers of vitamin E were also formed (Tibia samples at this stage are referred to as ‘Tibia-VEPE-Sterile’), Furthermore, two tocopherol-derived aldehydes (aldehyde 5-formyl-γ-tocopherol and aldehyde 7-formyl-γ-tocopherol) were also formed but at very low concentrations especially in the Tibia-VEPE-Sterile samples. The question of whether vitamin E becomes chemically reacted (grafted) onto the polymer matrix during the manufacturing process of the Tibia is also addressed.

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There is a commonly presumed link among sexual risk behavior, substance use, and other psychosocial factors among adolescents. However, these relationships have been relatively understudied in detained, low-income, minority, substance abusing adolescents. This study addresses this gap in the literature with a secondary data analysis based on a sample of adolescent offenders in two detention and treatment centers in Miami-Dade County. Univariate, bivariate statistical analysis and multivariate logistic regressions were conducted on baseline data from structured interviews with 455 adolescents participating in an NIH funded prevention intervention. Data were analyzed to assess relationships among self-reported substance use, STD history, HIV/AIDS knowledge, condom use, condom use attitudes, and skills, peer and parental approval to use condoms, and race/ethnicity. The adolescent sample was 74.1% male, and 25.9% female and 35.4% African American, 25.1% non-African American Latino, 11.2% White, and 28.4% of other race/ethnicity categories. The mean age was 15.6 years. Results suggested that alcohol use (p < 0.001) and use of marijuana, cocaine and other drugs (p < 0.001) are significant variables when explaining the variability in sexual risk behaviors. Results also suggested that unprotected vaginal, anal, and oral sex increased with higher alcohol and drug use (p < 0.001) and that positive attitudes about personally using condoms (p < 0.001) were also significantly related to condom use. Logistic regressions showed that race/ethnicity was a significant control variable when explaining the variability of condom use. Being White and Latino were significantly associated with less condom use during oral and anal sex when compared to other racial/ethnic groups. These results indicated that risky sexual behavior and HIV infection risk are significantly associated with substance use, particularly alcohol use. Therefore, proper screening and identification of alcohol use, and condom use attitudes could maximize the efficacy of referrals to programs targeting both issues and increase the potential for appropriate primary and secondary prevention and treatment among adolescent detainees.

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The presence of harmful algal blooms (HAB) is a growing concern in aquatic environments. Among HAB organisms, cyanobacteria are of special concern because they have been reported worldwide to cause environmental and human health problem through contamination of drinking water. Although several analytical approaches have been applied to monitoring cyanobacteria toxins, conventional methods are costly and time-consuming so that analyses take weeks for field sampling and subsequent lab analysis. Capillary electrophoresis (CE) becomes a particularly suitable analytical separation method that can couple very small samples and rapid separations to a wide range of selective and sensitive detection techniques. This paper demonstrates a method for rapid separation and identification of four microcystin variants commonly found in aquatic environments. CE coupled to UV and electrospray ionization time-of-flight mass spectrometry (ESI-TOF) procedures were developed. All four analytes were separated within 6 minutes. The ESI-TOF experiment provides accurate molecular information, which further identifies analytes.