Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 120
Filtrar
Más filtros

País/Región como asunto
Intervalo de año de publicación
1.
Proc Natl Acad Sci U S A ; 115(12): 3072-3077, 2018 03 20.
Artículo en Inglés | MEDLINE | ID: mdl-29483242

RESUMEN

The extent of increasing anthropogenic impacts on large marine vertebrates partly depends on the animals' movement patterns. Effective conservation requires identification of the key drivers of movement including intrinsic properties and extrinsic constraints associated with the dynamic nature of the environments the animals inhabit. However, the relative importance of intrinsic versus extrinsic factors remains elusive. We analyze a global dataset of ∼2.8 million locations from >2,600 tracked individuals across 50 marine vertebrates evolutionarily separated by millions of years and using different locomotion modes (fly, swim, walk/paddle). Strikingly, movement patterns show a remarkable convergence, being strongly conserved across species and independent of body length and mass, despite these traits ranging over 10 orders of magnitude among the species studied. This represents a fundamental difference between marine and terrestrial vertebrates not previously identified, likely linked to the reduced costs of locomotion in water. Movement patterns were primarily explained by the interaction between species-specific traits and the habitat(s) they move through, resulting in complex movement patterns when moving close to coasts compared with more predictable patterns when moving in open oceans. This distinct difference may be associated with greater complexity within coastal microhabitats, highlighting a critical role of preferred habitat in shaping marine vertebrate global movements. Efforts to develop understanding of the characteristics of vertebrate movement should consider the habitat(s) through which they move to identify how movement patterns will alter with forecasted severe ocean changes, such as reduced Arctic sea ice cover, sea level rise, and declining oxygen content.


Asunto(s)
Migración Animal , Bases de Datos Factuales , Océanos y Mares , Vertebrados , Animales , Ecosistema
2.
J Dairy Sci ; 104(5): 5643-5651, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33663816

RESUMEN

In this study, we evaluated the monitoring of tick fever (TF) in a Brazilian dairy farm in the Minas Gerais state, Brazil, from July 10 to August 4, 2018. We aimed to identify diagnostic and treatment flaws in the protocol adopted by the farm, and to establish a novel and accurate TF monitoring protocol based on precision dairy farming and rational use of antimicrobials and antiparasitic drugs, while evaluating the economic benefits of the proposed strategy. We monitored TF in 395 heifer calves aged between 3 and 14 mo. According to the farm's standard protocol, all calves with an increase of 0.5°C in rectal temperature compared with the previous week's measurement were treated for Anaplasma spp. and Babesia spp. Blood smears were collected from the tail tip of the treated calves. During the last week of the study, we prepared blood smears of all calves regardless of treatment indication. Economic analysis was performed. The results indicated that at least 56.86% (261/459) of the calves did not require treatment for TF, whereas only 23.09% (106/459) had treatment indications. Negative blood smears (45.97%; 211/459) indicated the possibility of calves being affected by another disease or a condition that was not being adequately treated or those not necessarily sick. These results demonstrate the excessive use of medications, representing a direct economic loss, in addition to potentially favoring the occurrence of resistance to antimicrobials. In contrast, 9.42% (26/276) of calves had no treatment indication based on rectal temperature but had treatment indications based on blood smears. Only 5.73% (42/735) of blood smears had co-infection with hemopathogens, and none had triple co-infection. Therefore, we proposed the monitoring of TF using rectal temperature and microscopic analysis. If implemented, this strategy would result in a direct annual savings of approximately $22,638.96 (77.99%) related to medication for the treatment of TF. Therefore, implementing the proposed protocol would be cheaper than treatment based only on rectal temperatures. The currently implemented TF protocols overestimate the occurrence of TF, resulting in overtreatment. Thus, implementing a TF monitoring protocol based on a microscopy tool is justified, with benefits including rational use of medication, potential to generate savings, and reduced morbidity and mortality rates, in addition to enabling other diagnoses.


Asunto(s)
Babesiosis , Enfermedades de los Bovinos , Garrapatas , Animales , Brasil , Bovinos , Enfermedades de los Bovinos/tratamiento farmacológico , Granjas , Femenino
3.
Appl Opt ; 59(25): 7720-7725, 2020 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-32902474

RESUMEN

Double layer thin films, mechanically stable and adhering to glass, were produced through the sol-gel process, using tetraethyl orthosilicate and titanium butoxide as precursors. The refractive index of the titania and silica-titania composite layers were typically 2.1 and 1.7, and their physical thicknesses were approximately 65 nm and 81 nm, respectively, as determined by ellipsometry. These optical constants allowed attainment of quarter-wave optical thicknesses at the center of the visible spectrum (550 nm) as designed, with an increase of 3.4% in transmittance. The nanometric surface roughness, measured by optical profilometry, was effective to decrease light scattering and water contact angles to below 10°. As novelty in dip-coated sol-gel films, superhydrophilicity for self-cleaning, antifogging, and antireflection in the mid-visible spectrum were simultaneously attained with durability of 9 weeks in the dark. Further application of UV light allowed regeneration of contact angles for self-cleaning.

4.
Ecol Appl ; 29(6): e01947, 2019 09.
Artículo en Inglés | MEDLINE | ID: mdl-31183944

RESUMEN

Telemetry is a key, widely used tool to understand marine megafauna distribution, habitat use, behavior, and physiology; however, a critical question remains: "How many animals should be tracked to acquire meaningful data sets?" This question has wide-ranging implications including considerations of statistical power, animal ethics, logistics, and cost. While power analyses can inform sample sizes needed for statistical significance, they require some initial data inputs that are often unavailable. To inform the planning of telemetry and biologging studies of marine megafauna where few or no data are available or where resources are limited, we reviewed the types of information that have been obtained in previously published studies using different sample sizes. We considered sample sizes from one to >100 individuals and synthesized empirical findings, detailing the information that can be gathered with increasing sample sizes. We complement this review with simulations, using real data, to show the impact of sample size when trying to address various research questions in movement ecology of marine megafauna. We also highlight the value of collaborative, synthetic studies to enhance sample sizes and broaden the range, scale, and scope of questions that can be answered.


Asunto(s)
Ecología , Ecosistema , Animales , Tamaño de la Muestra , Telemetría
5.
Int J Immunogenet ; 44(6): 350-355, 2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-29105301

RESUMEN

The effect of HLA-G 14 bp Ins/Del polymorphism (rs371194629) on the risk of preeclampsia has been assessed in several populations, yet the results are still conflicting. Lack of power due to small sample sizes is a common cause of inconsistencies in genetic association studies. We aimed to test whether the maternal polymorphism is associated with preeclampsia, eclampsia or HELLP syndrome (acronym for Hemolysis, Elevation of Liver enzymes, Low Platelets). To achieve a statistical power greater than 0.90, a total of 741 women (332 controls, 246 preeclampsia, 57 eclampsia and 106 HELLP) were genotyped for the 14-bp Ins/Del polymorphism. The genetic association with disease status was assessed by Fisher's exact test and odds ratio (OR) estimates using logistic regression model adjusted for maternal age and parity status. Allele and genotype distributions were the same between control and case groups (p > .05). The polymorphism was not associated with the risk of developing preeclampsia [OR = 0.93 (0.72-1.19); p = .541], or eclampsia [OR = 0.90 (0.60-1.38); p = .628] nor HELLP syndrome [OR = 0.92 (0.66-1.28); p = .628]. This well-powered study clearly demonstrates that the maternal HLA-G 14-bp Ins/Del polymorphism is not associated with preeclampsia risk. However, as the offspring genotypes were not evaluated here, we could not rule out the effect of the foetal genotype on the preeclampsia pathogenesis.


Asunto(s)
Emparejamiento Base/genética , Estudios de Asociación Genética , Predisposición Genética a la Enfermedad , Antígenos HLA-G/genética , Mutación INDEL/genética , Polimorfismo Genético , Preeclampsia/genética , Eliminación de Secuencia/genética , Adulto , Alelos , Femenino , Humanos , Modelos Logísticos , Edad Materna , Fenotipo , Embarazo , Factores de Riesgo , Adulto Joven
6.
Microbiology (Reading) ; 159(Pt 8): 1725-1735, 2013 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-23760820

RESUMEN

Colonization surface antigens (CSs) represent key virulence-associated factors of enterotoxigenic Escherichia coli (ETEC) strains. They are required for gut colonization, the first step of the diarrhoeal disease process induced by these bacteria. One of the most prevalent CSs is CS21, or longus, a type IV pili associated with bacterial self-aggregation, protection against environmental stresses, biofilm formation and adherence to epithelial cell lines. The objectives of this study were to assess the role of CS21 in adherence to primary intestinal epithelial cells and to determine if CS21 contributes to the pathogenesis of ETEC infection in vivo. We evaluated adherence of a CS21-expressing wild-type ETEC strain and an isogenic CS21-mutant strain to pig-derived intestinal cell lines. To determine the role of CS21 in pathogenesis we used the above ETEC strains in a neonatal mice challenge infection model to assess mortality. Quantitative adherence assays confirmed that ETEC adheres to primary intestinal epithelial cells lines in a CS21-dependent manner. In addition, the CS21-mediated ETEC adherence to cells was specific as purified LngA protein, the CS21 major subunit, competed for binding with the CS21-expressing ETEC while specific anti-LngA antibodies blocked adhesion to intestinal cells. Neonatal DBA/2 mice died after intra-stomach administration of CS21-expressing strains while lack of CS21 expression drastically reduced the virulence of the wild-type ETEC strain in this animal model. Collectively these results further support the role of CS21 during ETEC infection and add new evidence on its in vivo relevance in pathogenesis.


Asunto(s)
Adhesinas Bacterianas/metabolismo , Adhesión Bacteriana , Toxinas Bacterianas/metabolismo , Escherichia coli Enterotoxigénica/fisiología , Escherichia coli Enterotoxigénica/patogenicidad , Células Epiteliales/microbiología , Proteínas de Escherichia coli/metabolismo , Fimbrias Bacterianas/fisiología , Adhesinas Bacterianas/genética , Animales , Animales Recién Nacidos , Toxinas Bacterianas/genética , Células Cultivadas , Infecciones por Escherichia coli/microbiología , Infecciones por Escherichia coli/patología , Proteínas de Escherichia coli/genética , Eliminación de Gen , Ratones , Ratones Endogámicos DBA , Análisis de Supervivencia , Porcinos , Virulencia , Factores de Virulencia/genética , Factores de Virulencia/metabolismo
7.
Water Sci Technol ; 61(6): 1363-72, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-20351414

RESUMEN

The use of ultrasound as pre-treatment to improve anaerobic digestion of secondary sludge has been established as a promising technology. There are great differences between lab scale and full-scale devices, regarding the relationship between the disintegration achieved and the energy supplied. Based on economic aspects, most of the full-scale plants use partial-stream instead of the full-stream sonication, which affects biogas production and digestate dewatering characteristics. A laboratory scale operation combining ultrasound and anaerobic digestion (batch tests) has been performed, determining the relationship between the ratio of sonicated sludge fed and the methane production, SCOD removal and capillary suction time after 20-day anaerobic biodegradation, in order to check the possible benefits of part-stream versus full-stream sonication. Additional incubation was also evaluated, searching for an optimum process combining ultrasound and 24-h incubation pretreatment. Results showed that by sonicating fresh WAS at 25,700 kJ/kg TS biogas yield increased linearly with the percentage of sonicated WAS in the substrate, from 248 (control reactor) to 349 mL CH(4)/g VS (41% increase in full-stream sonication). By incubation (24 h, 55 degrees C), 325 mL CH(4)/g VS were obtained (31% increase), but the digestion of the soluble compounds generated during incubation of sonicated sludge appeared to be less degradable compared to those solubilised by ultrasound or incubation alone, which showed no benefit in combining both treatments. Post-digestion dewatering deteriorated for both part-stream and full-stream sonication, and CST values were constant (74% higher than the control digestate) from 30% to 100% sonicated sludge.


Asunto(s)
Reactores Biológicos , Aguas del Alcantarillado , Ultrasonido , Eliminación de Residuos Líquidos/métodos , Anaerobiosis , Factores de Tiempo , Agua
8.
Extr Ind Soc ; 7(4): 1347-1350, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-32895631

RESUMEN

The COVID-19 pandemic exposes both conflict and cooperation in artisanal and small-scale gold mining in the Brazilian Amazon. Reporting on the experiences of artisanal and small-scale gold miners (garimpeiros, in Brazilian Portuguese), we show how, on the one hand, the pandemic challenges an already precarious working system that could lead garimpeiros, often invisible to public policies, to positions of further vulnerability; and, on the other hand, highlights the capacity of garimpeiros to self-organize and navigate the difficulties by finding alternative solutions to cope with the crisis. This leads us to argue that emerging strategies of cooperation, related to self-organization and communication channels have the potential to provide experiences useful for processes of conflict transformation in the post-crisis. We acknowledge that much depends on the severity of the crisis and its manifestations in the region; nevertheless, the potential for constructive outcomes from the crisis should not be disregarded.

9.
Artículo en Inglés | MEDLINE | ID: mdl-19193996

RESUMEN

Maltose-binding protein is the periplasmic component of the ABC transporter responsible for the uptake of maltose/maltodextrins. The Xanthomonas axonopodis pv. citri maltose-binding protein MalE has been crystallized at 293 K using the hanging-drop vapour-diffusion method. The crystal belonged to the primitive hexagonal space group P6(1)22, with unit-cell parameters a = 123.59, b = 123.59, c = 304.20 A, and contained two molecules in the asymetric unit. It diffracted to 2.24 A resolution.


Asunto(s)
Proteínas Bacterianas/química , Proteínas Portadoras/química , Xanthomonas axonopodis/química , Proteínas Arqueales/química , Proteínas Arqueales/metabolismo , Proteínas Bacterianas/metabolismo , Proteínas Portadoras/metabolismo , Secuencia Conservada , Cristalización , Recolección de Datos/métodos , Maltosa/química , Maltosa/metabolismo , Proteínas de Unión a Maltosa , Polisacáridos/química , Polisacáridos/metabolismo , Relación Estructura-Actividad , Xanthomonas axonopodis/patogenicidad
10.
Braz J Microbiol ; 40(2): 333-8, 2009 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-24031368

RESUMEN

No effective vaccine or immunotherapy is presently available for patients with the hemolytic uremic syndrome (HUS) induced by Shiga-like toxin (Stx) produced by enterohaemorragic Escherichia coli (EHEC) strains, such as those belonging to the O157:H7 serotype. In this work we evaluated the performance of Bacillus subtilis strains, a harmless spore former gram-positive bacterium species, as a vaccine vehicle for the expression of Stx2B subunit (Stx2B). A recombinant B. subtilis vaccine strain expressing Stx2B under the control of a stress inducible promoter was delivered to BALB/c mice via oral, nasal or subcutaneous routes using both vegetative cells and spores. Mice immunized with vegetative cells by the oral route developed low but specific anti-Stx2B serum IgG and fecal IgA responses while mice immunized with recombinant spores developed anti-Stx2B responses only after administration via the parenteral route. Nonetheless, serum anti-Stx2B antibodies raised in mice immunized with the recombinant B. subtilis strain did not inhibit the toxic effects of the native toxin, both under in vitro and in vivo conditions, suggesting that either the quantity or the quality of the induced immune response did not support an effective neutralization of Stx2 produced by EHEC strains.

11.
Hernia ; 23(6): 1065-1069, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31494807

RESUMEN

PURPOSE: To analyze pain scores after surgery in a group of patients submitted to inguinal hernia repair under peripheral nerve block with local or spinal anesthesia. METHODS: Fifty patients were divided into two groups (both with 25 patients each). In the first group the patients were submitted to herniorrhaphy under peripheral block and local anesthesia (LG) and in the other group the patients were submitted to the same procedure under spinal anesthesia (RG). The pain was assessed using the international visual analog pain scale at four different moments. The analysis cost of the procedure was performed using the hospital's average final cost, without including medical expenses. RESULTS: The groups were homogeneous in relation to the epidemiological and clinical features. There was no significant difference between the pain in the intraoperative period and in the return visit for both groups (p = 0.17 and p = 0.18). In the immediate postoperative period, both groups reported no pain at all. In general, the RG reported a greater pain score (16% for RG and 12% for LG). Complications were more frequent in patients submitted to spinal anesthesia (40% versus 8%) (p = 0.008). The surgical time was higher in the LG (39.3 ± 9.2 min) versus (28.7 ± 7.5 min) (p = 0.01). The average final cost of the procedure was US$ 100.98 for the LG and US$ 166.19 for the RG (p = 0.00). CONCLUSION: The inguinal hernioplastia under local anesthesia plus sedation is a safe method, with a low incidence of complications, great acceptance by patients and less expensive.


Asunto(s)
Anestesia Local , Anestesia Raquidea , Hernia Inguinal/cirugía , Herniorrafia , Bloqueo Nervioso , Dolor Postoperatorio/prevención & control , Adulto , Anciano , Sedación Consciente , Femenino , Ingle/cirugía , Humanos , Periodo Intraoperatorio , Masculino , Persona de Mediana Edad , Dimensión del Dolor , Dolor Postoperatorio/diagnóstico , Dolor Postoperatorio/etiología , Periodo Posoperatorio
12.
J Bacteriol ; 190(7): 2400-10, 2008 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-18223074

RESUMEN

The natural diversity of the elt operons, encoding the heat-labile toxin LT-I (LT), carried by enterotoxigenic Escherichia coli (ETEC) strains isolated from humans was investigated. For many years, LT was supposed to be represented by a rather conserved toxin, and one derivative, produced by the reference H10407 strain, was intensively studied either as a virulence factor or as a vaccine adjuvant. Amplicons encompassing the two LT-encoding genes (eltA and eltB) of 51 human-derived ETEC strains, either LT(+) (25 strains) only or LT(+)/ST(+) (26 strains), isolated from asymptomatic (24 strains) or diarrheic (27 strains) subjects, were subjected to restriction fragment length polymorphism (RFLP) analysis and DNA sequencing. Seven polymorphic RFLP types of the H10407 strain were detected with six (BsaI, DdeI, HhaI, HincII, HphI, and MspI) restriction enzymes. Additionally, the single-nucleotide polymorphic analysis revealed 50 base changes in the elt operon, including 21 polymorphic sites at eltA and 9 at eltB. Based on the deduced amino acid sequences, 16 LT types were identified, including LT1, expressed by the H10407 strain and 23 other strains belonging to seven different serotypes, and LT2, expressed by 11 strains of six different serotypes. In vitro experiments carried out with purified toxins indicated that no significant differences in GM1-binding affinity could be detected among LT1, LT2, and LT4. However, LT4, but not other toxin types, showed reduced toxic activities measured either in vitro with cultured cells (Y-1 cells) or in vivo in rabbit ligated ileal loops. Collectively, these results indicate that the natural diversity of LTs produced by wild-type ETEC strains isolated from human hosts is considerably larger than previously assumed and may impact the pathogeneses of the strains and the epidemiology of the disease.


Asunto(s)
Escherichia coli Enterotoxigénica/genética , Enterotoxinas/genética , Proteínas de Escherichia coli/genética , Variación Genética , Animales , Línea Celular , Enzimas de Restricción del ADN/metabolismo , Escherichia coli Enterotoxigénica/clasificación , Escherichia coli Enterotoxigénica/aislamiento & purificación , Enterotoxinas/química , Enterotoxinas/metabolismo , Ensayo de Inmunoadsorción Enzimática , Infecciones por Escherichia coli/microbiología , Proteínas de Escherichia coli/química , Proteínas de Escherichia coli/metabolismo , Regulación Bacteriana de la Expresión Génica , Calor , Humanos , Íleon/microbiología , Ratones , Datos de Secuencia Molecular , Fenotipo , Filogenia , Reacción en Cadena de la Polimerasa , Polimorfismo de Longitud del Fragmento de Restricción , Polimorfismo de Nucleótido Simple , Estructura Secundaria de Proteína , Conejos , Análisis de Secuencia de ADN , Serotipificación
13.
Mem Inst Oswaldo Cruz ; 103(6): 606-10, 2008 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-18949334

RESUMEN

In the present study we investigated the flagellin-specific serum (IgG) and fecal (IgA) antibody responses elicited in BALB/c mice immunized with isogenic mutant derivatives of the attenuated Salmonella enterica serovar Typhimurium (S. Typhimurium) SL3261 strain expressing phase 1 (FliCi), phase 2 (FljB), or no endogenous flagellin. The data reported here indicate that mice orally immunized with recombinant S. Typhimurium strains do not mount significant systemic or secreted antibody responses to FliCi, FljB or heterologous B-cell epitopes genetically fused to FliCi. These findings are particularly relevant for those interested in the use of flagellins as molecular carriers of heterologous antigens vectored by attenuated S. Typhimurium strains.


Asunto(s)
Anticuerpos Antibacterianos/sangre , Flagelina/inmunología , Vacunas contra la Salmonella/inmunología , Salmonella typhimurium/inmunología , Administración Oral , Animales , Vacunas Bacterianas/inmunología , Ratones , Ratones Endogámicos BALB C , Vacunas contra la Salmonella/administración & dosificación , Vacunas Atenuadas/inmunología
14.
Genet Mol Res ; 7(1): 117-26, 2008 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-18273827

RESUMEN

The oligopeptide-binding protein, OppA, binds and ushers oligopeptide substrates to the membrane-associated oligopeptide permease (Opp), a multi-component ABC-type transporter involved in the uptake of oligopeptides expressed by several bacterial species. In the present study, we report the cloning, purification, refolding and conformational analysis of a recombinant OppA protein derived from Xanthomonas axonopodis pv. citri (X. citri), the etiological agent of citrus canker. The oppA gene was expressed in Escherichia coli BL21 (DE3) strain under optimized inducing conditions and the recombinant protein remained largely insoluble. Solubilization was achieved following refolding of the denatured protein. Circular dichroism analysis indicated that the recombinant OppA protein preserved conformational features of orthologs expressed by other bacterial species. The refolded recombinant OppA represents a useful tool for structural and functional analyses of the X. citri protein.


Asunto(s)
Proteínas Bacterianas/aislamiento & purificación , Proteínas Bacterianas/metabolismo , Proteínas Portadoras/metabolismo , Proteínas de Transporte de Membrana/aislamiento & purificación , Proteínas de Transporte de Membrana/metabolismo , Pliegue de Proteína , Xanthomonas axonopodis/genética , Secuencia de Aminoácidos , Proteínas Bacterianas/química , Proteínas Bacterianas/genética , Secuencia de Bases , Proteínas Portadoras/genética , Proteínas Portadoras/aislamiento & purificación , Dicroismo Circular , Clonación Molecular , Biología Computacional/métodos , Escherichia coli/genética , Proteínas de Transporte de Membrana/química , Proteínas de Transporte de Membrana/genética , Datos de Secuencia Molecular , Operón , Plásmidos , Conformación Proteica , Desnaturalización Proteica , Renaturación de Proteína , Señales de Clasificación de Proteína , Estructura Secundaria de Proteína , Estructura Terciaria de Proteína , Proteínas Recombinantes/química , Proteínas Recombinantes/aislamiento & purificación , Proteínas Recombinantes/metabolismo , Solubilidad , Especificidad por Sustrato , Xanthomonas axonopodis/metabolismo
15.
Genet Mol Res ; 6(4): 1169-77, 2007 Dec 11.
Artículo en Inglés | MEDLINE | ID: mdl-18273810

RESUMEN

The oligopeptide-binding protein, OppA, ushers oligopeptide substrates to the membrane-associated oligopeptide permease (Opp), a multi-component ABC-type transporter involved in the uptake of oligopeptides by several bacterial species. In the present study, we report a structural model and an oligopeptide docking analysis of the OppA protein expressed by Xanthomonas axonopodis pv. citri (X. citri), the etiological agent of citrus canker. The X. citri OppA structural model showed a conserved three-dimensional structure, irrespective of the low amino acid identities with previously defined structures of Bacillus subtilis and Salmonella typhimurium orthologs. Oligopeptide docking analysis carried out with the proposed model indicated that the X. citri OppA preferentially binds tri- and tetrapeptides. The present study represents the first structural analysis of an OppA ortholog expressed by a phytopathogen and contributes to the understanding of the physiology and nutritional strategies of X. citri.


Asunto(s)
Proteínas Bacterianas/química , Proteínas Bacterianas/metabolismo , Proteínas Portadoras/química , Proteínas Portadoras/metabolismo , Lipoproteínas/química , Lipoproteínas/metabolismo , Oligopéptidos/metabolismo , Xanthomonas axonopodis/metabolismo , Secuencia de Aminoácidos , Proteínas Bacterianas/genética , Sitios de Unión , Proteínas Portadoras/genética , Ligandos , Lipoproteínas/genética , Modelos Moleculares , Datos de Secuencia Molecular , Oligopéptidos/química , Enfermedades de las Plantas/microbiología , Unión Proteica , Conformación Proteica , Xanthomonas axonopodis/genética , Xanthomonas axonopodis/patogenicidad
16.
Artículo en Inglés | MEDLINE | ID: mdl-16511325

RESUMEN

Xanthomonas axonopodis pv. citri ModA protein is the ABC periplasmic binding component responsible for the capture of molybdate. The protein was crystallized with sodium molybdate using the hanging-drop vapour-diffusion method in the presence of PEG or sulfate. X-ray diffraction data were collected to a maximum resolution of 1.7 A using synchrotron radiation. The crystal belongs to the orthorhombic space group C222(1), with unit-cell parameters a = 68.15, b = 172.14, c = 112.04 A. The crystal structure was solved by molecular-replacement methods and structure refinement is in progress.


Asunto(s)
Transportadoras de Casetes de Unión a ATP/química , Molibdeno/metabolismo , Proteínas de Unión Periplasmáticas/química , Xanthomonas/química , Cristalización/métodos , Cristalografía por Rayos X , Escherichia coli/metabolismo , Proteínas Recombinantes/química
17.
J Comp Pathol ; 154(2-3): 157-60, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-26852343

RESUMEN

Parasitological methods are the most specific procedures used for the diagnosis of Leishmania spp. infection, but their limited sensitivity poses a disadvantage and prompts the need for alternatives. The choice of site for sample collection influences diagnostic sensitivity. The combination of an accurate diagnostic method and a technique that allows large-scale field studies is highly desirable to enhance the investigation of Leishmania spp. infection in dogs, especially in endemic regions. The bone marrow is a good target for the detection of Leishmania spp. in dogs. In this context, bone marrow aspiration is rapid and less invasive compared with biopsy procedures, and also enables cell block processing, paraffin wax embedding and the sectioning of samples for further histological and immunohistochemical analyses. The aim of this study was to describe for the first time parasitological methods (immunohistochemistry [IHC] and histopathology) using the cell block technique with bone marrow aspirates for the diagnosis of Leishmania spp. infection in dogs. Bone marrow aspiration was performed in 45 dogs from an area endemic for visceral leishmaniosis for parasitological culture and the cell block technique (histopathology and IHC). Fourteen (31.1%) dogs tested positive for Leishmania spp. by IHC, six (13.3%) by parasitological culture and four (8.9%) by histopathology. Cell block IHC was a useful tool for the diagnosis of canine visceral leishmaniosis. Further studies should be conducted to validate this method for routine epidemiological screening.


Asunto(s)
Médula Ósea/parasitología , Enfermedades de los Perros/diagnóstico , Inmunohistoquímica/métodos , Leishmaniasis Visceral/veterinaria , Animales , Biopsia con Aguja , Médula Ósea/patología , Perros , Leishmania infantum , Leishmaniasis Visceral/diagnóstico
18.
J Anim Sci ; 94(1): 401-5, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26812345

RESUMEN

This study compared reproductive performance of cows vaccinated against the foot-and-mouth disease (FMD) virus before timed AI or during early pregnancy (Exp. 1), as well as rectal temperature (RT) and plasma concentrations of the acute-phase protein haptoglobin in cattle vaccinated or not against the FMD virus (Exp. 2). Cattle utilized in Exp. 1 and 2 originated from herds with no historical occurrences of FMD and that received vaccination against the FMD virus biannually. In Exp. 1, 604 lactating, multiparous, nonpregnant Nelore cows were randomly assigned on d -31 of the experiment to receive 1) vaccination against the FMD virus on d ≥ 31 (VACPRE; = 291) and 2) vaccination against FMD virus on d 30 (VACGEST; = 313). From d -11 to 0, all cows were assigned to an estrus synchronization + timed AI (d 0) protocol. Pregnancy status to AI was verified on d 30 and 90 via transrectal ultrasonography. A treatment × day interaction was detected ( < 0.01) for pregnancy rates to AI, which were similar ( = 0.17) between VACPRE and VACGEST on d 30 (61.8% vs. 56.2%, respectively; SEM = 2.8) but greater ( < 0.01) for VACPRE on d 90 (59.4% vs. 46.9%, respectively; SEM = 2.8). Pregnancy loss from d 30 to 90 was greater ( < 0.01) in VACGEST compared with VACPRE (16.5% vs. 3.9%, respectively; SEM = 2.2). In Exp. 2, 40 pregnant Nelore females (20 nulliparous and 20 multiparous cows; BCS = 4.73 ± 0.12) were ranked by parity and assigned to receive (VAC; = 20) or not receive (NOVAC; = 20) vaccination against the FMD virus. Blood samples were collected and RT was recorded before (h 0) and 24, 72, 120, and 168 h after treatment administration. Treatment × day interactions were detected ( < 0.01) for RT and plasma haptoglobin. The RT was greater ( < 0.01) in VAC compared with NOVAC at 24 h after treatment administration and was similar ( ≥ 0.31) between treatments at all other sampling hours. Plasma haptoglobin concentration was similar ( = 0.98) between VAC and NOVAC before treatment administration ( = 0.48) and greater ( < 0.01) in VAC at 24, 72, 120, and 168 h after treatment administration. In summary, vaccinating beef cows against the FMD virus resulted in a 4-fold increase in pregnancy loss when the vaccine was administered 30 d after timed AI compared with 31 d before timed AI. These outcomes can be associated with inflammatory and acute-phase reactions elicited by the FMD vaccine, which are known to impair pregnancy maintenance in cattle.


Asunto(s)
Enfermedades de los Bovinos/prevención & control , Virus de la Fiebre Aftosa , Fiebre Aftosa/prevención & control , Esquemas de Inmunización , Reproducción , Vacunas Virales/inmunología , Aborto Veterinario , Proteínas de Fase Aguda , Animales , Bovinos , Femenino , Inflamación/inducido químicamente , Inflamación/veterinaria , Inseminación Artificial/veterinaria , Lactancia , Paridad , Embarazo , Vacunas Virales/efectos adversos
19.
Artículo en Portugués | LILACS | ID: biblio-1353484

RESUMEN

RESUMO: Introdução: A dissecção da artéria carótida (DAC) tem como uma das principais repercussões o Acidente Vascular Cerebral isquêmico (AVCi) em indivíduos jovens previamente saudáveis. É comum que nas DAC traumáticas, como em acidentes automobilísticos, o paciente seja submetido à investigação mais complexa com exames de imagem. Estes permitem um diagnóstico precoce e, portanto, um tratamento, reduzindo as chances de sequelas. Todavia, cau-sas não traumáticas com desfecho de DAC já foram relatadas, como as causas odontológicas. Objetivo: Contribuir para valorização diagnóstica da DAC não traumática e profilaxia de AVC subsequente. Métodos: Relatamos um caso de dissecção não aneurismática das artérias carótidas internas (ACI) pós-procedimento odontológico com desfecho de AVC bilateral em paciente de 52 anos. Resultados: Devido à forte associação de DAC a fatores traumáticos, em um primeiro contato com a paciente não foram levantadas suspeitas da ocorrência de DAC nem de AVC (ausência de déficit focal). Porém, tardiamente, foi identificada oclusão da ACI à esquerda e estenose na ACI direita, resultando em dois AVCs e incapacidade funcional severa na alta. Conclusão: O diagnóstico da DAC é um desafio, em especial por tratar-se de uma lesão de etiologia multifatorial. No entanto, seu reconhecimento precoce afetará diretamente o desfecho do paciente. Portanto, na presença de eventuais sintomas de alerta, faz-se necessário um meticuloso ques-tionamento sobre as últimas atividades do indivíduo. Este estudo alerta para a adoção de condutas profiláticas na ocorrência de fatores causais como hiperextensão cervical prolongada ou movimentos súbitos da cervical. (AU)


ABSTRACT: Introduction: Carotid artery dissection (CAD) has the ischemic stroke as one of the main repercussions in pre-viously healthy young individuals. It is common that in traumatic CAD, as in automobile accidents, the patient is subjected to a more complex investigation with imaging exams. These, allow an early diagnosis and, therefore, a treatment, reducing the chances of sequelae. However, non-traumatic causes with CAD outcomes have already been reported, such as dental causes. Objective: To contribute to the diagnostic valuation of non-traumatic CAD and subsequent stroke prophylaxis. Methods: We report a case of non-aneurysmatic dissection of the internal carotid arteries (ICA) after a dental procedure with evolution to bilateral stroke outcome in a 52-year-old patient. Results: Due to the strong association of CAD with traumatic factors, in a first contact with the patient there was no suspicion of CAD or stroke (absence of focal deficit). However, late, ICA occlusion on the left and stenosis on the right ICA were identified, resulting in two strokes and severe functional disability at discharge. Conclusion:The diagnosis of CAD is a challenge, especially since it is a multifactorial lesion. However, its early recognition will directly affect the patient's outcome. Therefore, in the presence of any warning symptoms, meticulous questioning about the individual's latest activities is necessary. This study alerts to the adoption of prophylactic conducts in the occurrence of causal factors such as prolonged cervical hyperextension or sudden movements of the cervical. (AU)


Asunto(s)
Humanos , Femenino , Persona de Mediana Edad , Disección de la Arteria Carótida Interna , Accidente Cerebrovascular , Implantación Dental , Accidente Cerebrovascular Isquémico
20.
Mol Oral Microbiol ; 31(5): 410-22, 2016 10.
Artículo en Inglés | MEDLINE | ID: mdl-26462737

RESUMEN

Bacterial ATP-binding cassette (ABC) transporters play a crucial role in the physiology and pathogenicity of different bacterial species. Components of ABC transporters have also been tested as target antigens for the development of vaccines against different bacterial species, such as those belonging to the Streptococcus genus. Streptococcus mutans is the etiological agent of dental caries, and previous studies have demonstrated that deletion of the gene encoding PstS, the substrate-binding component of the phosphate uptake system (Pst), reduced the adherence of the bacteria to abiotic surfaces. In the current study, we generated a recombinant form of the S. mutans PstS protein (rPstS) with preserved structural features, and we evaluated the induction of antibody responses in mice after sublingual mucosal immunization with a formulation containing the recombinant protein and an adjuvant derived from the heat-labile toxin from enterotoxigenic Escherichia coli strains. Mice immunized with rPstS exhibited systemic and secreted antibody responses, measured by the number of immunoglobulin A-secreting cells in draining lymph nodes. Serum antibodies raised in mice immunized with rPstS interfered with the adhesion of bacteria to the oral cavity of naive mice challenged with S. mutans. Similarly, mice actively immunized with rPstS were partially protected from oral colonization after challenge with the S. mutans NG8 strain. Therefore, our results indicate that S. mutans PstS is a potential target antigen capable of inducing specific and protective antibody responses after sublingual administration. Overall, these observations raise interesting perspectives for the development of vaccines to prevent dental caries.


Asunto(s)
Anticuerpos Antibacterianos/sangre , Caries Dental/prevención & control , Inmunización/métodos , Boca/microbiología , Proteínas de Unión a Fosfato/inmunología , Streptococcus mutans/crecimiento & desarrollo , Streptococcus mutans/inmunología , Adyuvantes Inmunológicos , Administración Sublingual , Animales , Antígenos Bacterianos/inmunología , Adhesión Bacteriana , Vacunas Bacterianas/inmunología , Caries Dental/microbiología , Escherichia coli Enterotoxigénica/química , Femenino , Inmunidad Mucosa , Inmunoglobulina A/análisis , Ratones , Proteínas de Unión a Fosfato/administración & dosificación , Proteínas Recombinantes/administración & dosificación , Proteínas Recombinantes/inmunología , Saliva/inmunología
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA