1,089 research outputs found
Colonization capacity and serum bactericidal activity of Haemophilus parasuis thy mutants
The bacterial thyA gene encodes the enzyme thymidylate synthase, which is essential for dTMP synthesis and, consequently, for DNA replication. In this work, a Haemophilus parasuis thyA mutant was constructed in order to analyze its colonization characteristics and its capacity to generate serum bactericidal activity in infected guinea pigs. The data showed that colonization by the H. parasuis thyA mutant was much less than that of the wild-type strain. Nevertheless, the mutant generated a strong immunogenic response in the host, as detected by measuring serum bactericidal activity. [Int Microbiol 2006; 9(4):297-301
Heterologous protective immunization elicited in mice by Pasteurella multocida fur ompH
Different strategies have been developed to produce vaccines against Pasteurella multocida. The approach described herein involves overexpression on the bacterial cell surface of Fur-regulated IROMPs (iron-regulated outer-membrane proteins). Accordingly, the ability of fur mutants to promote heterologous protection was examined in a Swiss mouse animal model. Two fur mutants derived from P. multocida were isolated, one of which was also defective in the OmpH protein. In mice challenged with virulent P. multocida, outer-membrane protein (OMP) extracts of fur cells conferred the same
protection as obtained with wild-type cells grown in iron-depleted medium. Total protection was achieved with 40 μg of OMP extract from the fur ompH mutant. Mice administered heat-inactivated fur ompH cells were 60% cross-protected. The presence of a galE mutation in these cells did not further increase the protection level. Additionally, cell disruption by sonication provoked a higher level of protection than conferred by heat-treated cells. Taken together, the results showed that P. multocida
fur ompH cells offer a simple and suitable approach for cross-protecting animals against infection with P. multocida. [Int Microbiol 2008; 11(1):17-24
Vaccination sequence effects on immunological response and tissue bacterial burden in paratuberculosis infection in a rabbit model
[EN] Paratuberculosis (PTB), a chronic granulomatous enteritis produced by Mycobacterium avium subspecies paratuberculosis (MAP), is considered as one of the diseases with the highest economic impact in the ruminant industry. Vaccination against MAP is recommended during the first months after birth on the basis that protection would be conferred before the first contact with mycobacteria. However, little is known about the therapeutic effect of MAP vaccination in controlled experimental conditions. The current study was designed to evaluate the efficacy of vaccination before and after challenge with MAP in a rabbit infection model. The rabbits were divided into four groups: non-infected control (NIC, n = 4), infected control challenged with MAP (IC, n = 5), vaccinated and challenged 1 month after with MAP (VSI, n = 5) and challenged with MAP and vaccinated 2 months later (IVS, n = 5). The results from this study show a quick increase in IFN-γ release upon stimulation with bovine, avian and johnin PPD in animals vaccinated before MAP challenge. All vaccinated animals show an increased humoral response as seen by western blot and ELISA. The final bacteriology index (considering tissue culture and qPCR) shows that the IC group was the most affected. Vaccination after infection (IVS) produced the lowest bacteriology index showing significant differences with the IC group (p = 0.034). In conclusion, vaccination against MAP shows positive effects in a rabbit model. However, vaccination after infection shows a slightly stronger protective effect compared to vaccination before infection, suggesting a therapeutic effect. This feature could be applied to previously infected adult animals under field conditionsSIThe authors thank Felix Blanco from the animal facilities (NEIKER-Tecnalia). This study was supported with funds from the Ministerio de Economía y Competitividad from the Spanish Government (AGL 2012-39818-C02-02). RA acknowledges support from the Departamento de Educación y Universidades of the Basque Government (BFI-2012-237
Cranberry
El arándano rojo o arándano rojo americano (Vaccinium macrocarpon Ait.) es una fruta muy consumida y apreciada que ha ganado popularidad con los años debido en parte a su contenido en compuestos beneficiosos para la salud humana. En el trabajo se consideran aspectos botánicos, composición nutricional y contenido en compuestos fitoquímicos, datos históricos y culturales e información sobre el cultivo de esta especie vegetal y sus variedades. También se considera su importancia económica y algunos aspectos relacionados con tratamientos postcosecha y biotecnología en relación con esta especie.Cranberry or American cranberry (Vaccinium macrocarpon Ait.) is a very popular fruit consumed and which has gained popularity over the years due in part to its content in compounds beneficial to human health. In this paper we consider botanical aspects, nutritional composition and content of phytochemicals, historical and cultural data and information on the cultivation of this plant species and varieties. It is also considered its economic importance and some aspects of postharvest treatments and biotechnology in relation to the species.Depto. de Genética, Fisiología y MicrobiologíaFac. de Ciencias BiológicasTRUEpu
Assessment of nutritional status and bone health in neurologically impaired children: a challenge in pediatric clinical practice
NTRODUCTION: neurologically impaired children frequently experience nutritional disorders and bone health complications. Our aim was firstly to analyze a method to interpret bone mineral density (BMD) accurately in neurologically impaired children. Secondly, to determine its relationship with the nutritional status and micronutrient levels in order to identify which factors are associated with low BMD. METHODS: a observational multicenter study was conducted in children with moderate-to-severe neurological impairment. Data collected included: medical records, anthropometric measures, hematologic and biochemical evaluation. BMD was measured with Dual-energy X-ray absorptiometry and z-scores were calculated adjusting for sex and chronological age. Secondly, BMD z-scores were calculated applying height age (age at which the child's height would be in 2nd percentile) instead of chronological age. RESULTS: fifty-two children were included (aged 4-16 years). Seventeen patients (32.7%) received feeding by gastrostomy tube. Height and BMI z-score were below 2SD in 64% and 31% of patients respectively, with normal mid upper arm circumference and skinfold thickness measurements. Low vitamin-D levels were found in 42% of cases. 50% of patients evidenced low BMD when calculated for chronological age, whereas only 34.5% showed BMD z-score <-2 when calculated for height age. No correlation was observed between BMD and vitamin-D levels, weight and height z-scores or age when BMD was calculated applying height age. CONCLUSIONS: the prevalence of low BMD is high in neurologically impaired children, and it is probably multifactorial. In these children, we suggest adjusting BMD for height age, in order not to over diagnose low BMD
Significant reduction in bacterial shedding and improvement in milk production in dairy farms after the use of a new inactivated paratuberculosis vaccine in a field trial
Hamiltonian Structure, Symmetries and Conservation Laws for a Generalized (2 + 1)-Dimensional Double Dispersion Equation
This paper considers a generalized double dispersion equation depending on a nonlinear
function f (u) and four arbitrary parameters. This equation describes nonlinear dispersive waves in
2 + 1 dimensions and admits a Lagrangian formulation when it is expressed in terms of a potential
variable. In this case, the associated Hamiltonian structure is obtained. We classify all of the Lie
symmetries (point and contact) and present the corresponding symmetry transformation groups.
Finally, we derive the conservation laws from those symmetries that are variational, and we discuss
the physical meaning of the corresponding conserved quantities
Crossover from ballistic to diffusive thermal transport in suspended graphene membranes
We report heat transport measurements on suspended single-layer graphene disks with radius of 150-1600 nm using a high-vacuum scanning thermal microscope. The results of this study revealed a radius-dependent thermal contact resistance between tip and graphene, with values between 1.15 and 1.52 × 10 KW. The observed scaling of thermal resistance with radius is interpreted in terms of ballistic phonon transport in suspended graphene discs with radius smaller than 775 nm. In larger suspended graphene discs (radius >775 nm), the thermal resistance increases with radius, which is attributed to in-plane heat transport being limited by phonon-phonon resistive scattering processes, which resulted in a transition from ballistic to diffusive thermal transport. In addition, by simultaneously mapping topography and steady-state heat flux signals between a self-heated scanning probe sensor and graphene with 17 nm thermal spatial resolution, we demonstrated that the surface quality of the suspended graphene and its connectivity with the Si/SiO substrate play a determining role in thermal transport. Our approach allows the investigation of heat transport in suspended graphene at sub-micrometre length scales and overcomes major limitations of conventional experimental methods usually caused by extrinsic thermal contact resistances, assumptions on the value of the graphene's optical absorbance and limited thermal spatial resolution
Alternative Vaccination Routes against Paratuberculosis Modulate Local Immune Response and Interference with Tuberculosis Diagnosis in Laboratory Animal Models
[EN] Paratuberculosis (PTB) is an enteric granulomatous disease caused by Mycobacterium avium subsp. paratuberculosis (MAP) that mainly aects ruminants. Current vaccines have shown to be cost-eective control reagents, although they are restricted due to cross-interference with bovine tuberculosis (bTB). Therefore, novel vaccination strategies are needed and this study is focused on evaluating alternative vaccination routes and their eect on the local immune response. The MAP oral challenge rabbit model was used to evaluate and compare an experimental inactivated MAP vaccine through oral (VOR) and intradermal (VID) routes. The VID group presented the highest proportion of animals with no visible lesions and the lowest proportion of animals with MAP positive tissues. Immunohistochemistry analysis revealed that the VID group presented a dominantly M1 polarized response indicating an ability to control MAP infection. In general, all vaccinated groups showed lower calprotectin levels compared to the non-vaccinated challenged group suggesting less active granulomatous lesions. The VID group showed some degree of skin test reactivity, whereas the same vaccine through oral administration was completely negative. These data show that PTB vaccination has an eect on macrophage polarization and that the route influences infection outcome and can also have an impact on bTB diagnosis. Future evaluation of new immunological products against mycobacterial diseases should consider assaying dierent vaccination routesSIThe research was funded by the Department of Economy and Infrastructures (DEI) of the Basque Government and partially by grant RTA 2017-00089-00-00 of the National Institute for Agronomic Research (INIA). R.A. held a pre-doctoral fellowship (BFI-2012-237) from the Department of Education, Universities and Research of the Basque Government and IL is recipient of a pre-doctoral fellowship from the DEI of the Basque Governmen
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