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Cheap, easy-to-produce oral vaccines are needed for control of coccidiosis in chickens to reduce the impact of this disease on welfare and economic performance. Saccharomyces cerevisiae yeast expressing three Eimeria tenella antigens were developed and delivered as heat-killed, freeze-dried whole yeast oral vaccines to chickens in four separate studies. After vaccination, E. tenella replication was reduced following low dose challenge (250 oocysts) in Hy-Line Brown layer chickens (p<0.01). Similarly, caecal lesion score was reduced in Hy-Line Brown layer chickens vaccinated using a mixture of S. cerevisiae expressing EtAMA1, EtIMP1 and EtMIC3 following pathogenic-level challenge (4,000 E. tenella oocysts; p<0.01). Mean body weight gain post-challenge with 15,000 E. tenella oocysts was significantly increased in vaccinated Cobb500 broiler chickens compared to mock-vaccinated controls (p<0.01). Thus, inactivated recombinant yeast vaccines offer cost-effective and scalable opportunities for control of coccidiosis, with relevance to broiler production and chickens reared in low-and middle-income countries (LMICs).
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Coccidiosis/veterinaria , Eimeria tenella/inmunología , Enfermedades de las Aves de Corral/parasitología , Proteínas Protozoarias/inmunología , Vacunas Antiprotozoos/inmunología , Animales , Pollos/inmunología , Pollos/parasitología , Coccidiosis/prevención & control , Eimeria tenella/crecimiento & desarrollo , Femenino , Masculino , Enfermedades de las Aves de Corral/prevención & control , Proteínas Protozoarias/genética , Vacunas Antiprotozoos/genética , Saccharomyces cerevisiae/inmunología , Vacunación/métodos , Vacunación/veterinaria , Vacunas de Subunidad/inmunologíaRESUMEN
Coccidiosis is a potentially severe enteritis caused by species of obligate intracellular parasites of the genus Eimeria. These parasites cause significant economic losses to the poultry industry, predominantly due to compromised efficiency of production as well as the cost of control. These losses were recently estimated to cost chicken producers approximately £10.4 billion worldwide annually. High levels of Eimeria infection cause clinical coccidiosis which is a significant threat to poultry welfare, and a pre-disposing contributory factor for necrotic enteritis. Control of Eimeria parasites and coccidiosis is therefore an important endeavour; multiple approaches have been developed and these are often deployed together. This review summarises current trends in strategies for control of Eimeria, focusing on three main areas: good husbandry, chemoprophylaxis and vaccination. There is currently no "perfect solution" and there are advantages and limitations to all existing methods. Therefore, the aim of this review is to present current control strategies and suggest how these may develop in the future.
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Fasciola hepatica, the liver fluke, is a trematode parasite that causes disease of economic importance in livestock. As a zoonosis this parasite also poses a risk to human health in areas where it is endemic. Population genetic studies can reveal the mechanisms responsible for genetic structuring (non-panmixia) within parasite populations and provide valuable insights into population dynamics, which in turn enables theoretical predictions of evolutionary dynamics such as the evolution of drug resistance. Here we genotyped 320 F. hepatica collected from 14 definitive hosts from four provinces in Argentina. STRUCTURE analysis indicated three population clusters, and principal coordinate analysis confirmed this, showing population clustering across provinces. Similarly, pairwise FST values amongst all four provinces were significant, with standardised pairwise FST (F'ST) ranging from 0.0754 to 0.6327. Therefore, population genetic structure was evident across these four provinces in Argentina. However, there was no evidence of deviation from Hardy-Weinberg equilibrium, so it appears that within these sub-populations there is largely random mating. We identified 263 unique genotypes, which gave a clonal diversity of 82%. Parasites with identical genotypes, clones, accounted for 26.6% of the parasites studied and were found in 12 of the 14 hosts studied, suggesting some clonemate transmission.
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Fasciola hepatica , Fascioliasis , Animales , Argentina/epidemiología , Fasciola hepatica/genética , Fascioliasis/epidemiología , Fascioliasis/veterinaria , Variación Genética , Genética de Población , Genotipo , HumanosRESUMEN
CD8+ T cells have been shown to play a critical role in the pathogenesis of experimental cerebral malaria (ECM) in mice, but their role in development of human cerebral malaria (HCM) remains unclear. Thus, in this study we have provided the first direct contrast of the accumulation of CD8+ T cells in the brain during HCM and ECM. HCM cases were from children who died of Plasmodium falciparum cerebral malaria at Queen Elizabeth Central Hospital (Malawi) between 2003 and 2010. ECM was induced by infecting C57BL/6J mice with P. berghei ANKA. We demonstrate similarities in the intracerebral CD8+ T cell responses in ECM and HCM, in particular an apparent shared choroid plexus-meningeal route of CD8+ T cell accumulation in the brain. Nevertheless, we also reveal some potentially important differences in compartmentalization of CD8+ T cells within the cerebrovascular bed in HCM and ECM.
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Encéfalo , Linfocitos T CD8-positivos , Malaria Cerebral , Malaria Falciparum , Plasmodium berghei/inmunología , Plasmodium falciparum/inmunología , Animales , Encéfalo/inmunología , Encéfalo/parasitología , Encéfalo/patología , Linfocitos T CD8-positivos/inmunología , Linfocitos T CD8-positivos/patología , Niño , Preescolar , Femenino , Humanos , Malaria Cerebral/inmunología , Malaria Cerebral/patología , Malaria Falciparum/inmunología , Malaria Falciparum/patología , Masculino , RatonesRESUMEN
Mal de Debarquement Syndrome is a neurological disorder of motion perception, triggered by external motion. This study aimed to determine the importance of psychosocial factors in relation to depression and quality of life in Mal de Debarquement Syndrome. A total of 66 participants with self-reported Mal de Debarquement Syndrome completed quality-of-life, symptom severity, stigma, depression, and illness intrusiveness measurements in this naturalistic correlational study. Mal de Debarquement Syndrome was associated with high levels of depression and illness intrusiveness. Illness intrusiveness mediated between stigma and quality of life; also the level of stigma moderated the effect of illness intrusiveness on quality of life. Targeted interventions aimed at alleviating psychological distress may improve quality of life in Mal de Debarquement Syndrome.
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Depresión/etiología , Calidad de Vida , Índice de Severidad de la Enfermedad , Estigma Social , Viaje/psicología , Adulto , Anciano , Femenino , Indicadores de Salud , Humanos , Masculino , Persona de Mediana Edad , Enfermedad Relacionada con los ViajesRESUMEN
BACKGROUND: Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a long-term, debilitating condition that impacts numerous areas of individuals' lives. The two predominant treatment options for ME/CFS are cognitive behavioral therapy and graded exercise therapy; however, many people have found these techniques unacceptable or even damaging. This pilot study aimed to evaluate the utility of a specialized online symptom management program for ME/CFS in comparison to an online meditation program in an effort to ascertain whether this tool could be a further option for those with ME/CFS. METHODS: THIS EXPERIMENTAL DESIGN CONSISTED OF TWO INTERVENTIONS: a specialized online symptoms management program (N=19) and a control intervention based on an online meditation website (N=9). A battery of questionnaires, including measures of multidimensional fatigue, illness-specific symptoms, perceived control, and mindful awareness, were completed before the participants commenced use of the programs and following 8 weeks' use. RESULTS: Significant differences were found in the areas of chance and powerful others' locus of control, and sleeping difficulties, but not in ME/CFS symptomatology overall. CONCLUSION: The specialized online program described in this study warrants further investigation, as it appears to influence perceived control and key ME/CFS symptoms over time.
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BACKGROUND: Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is characterized by persistent emotional, mental, and physical fatigue accompanied by a range of neurological, autonomic, neuroendocrine, immune, and sleep problems. Research has shown that psychosocial factors such as anxiety and depression as well as the symptoms of the illness, have a significant impact on the quality of life of people with ME/CFS. In addition, individuals may suffer from deficits in memory and concentration. This study set out to explore the relationships between variables which have been found to contribute to cognitive performance, as measured by prospective and retrospective memory, and cognitive failures. METHODS: Eighty-seven people with ME/CFS answered questionnaires measuring fatigue, depression, anxiety, social support, and general self-efficacy. These were used in a correlational design (multiple regression) to predict cognitive function (self-ratings on prospective and retrospective memory), and cognitive failures. RESULTS: Our study found that fatigue, depression, and general self-efficacy were directly associated with cognitive failures and retrospective (but not prospective) memory. CONCLUSION: Although it was not possible in this study to determine the cause of the deficits, the literature in this area leads us to suggest that although the pathophysiological mechanisms of ME/CFS are unclear, abnormalities in the immune system, including proinflammatory cytokines, can lead to significant impairments in cognition. We suggest that fatigue and depression may be a result of the neurobiological effects of ME/CFS and in addition, that the neurobiological effects of the illness may give rise to both fatigue and cognitive deficits independently.
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HYPOTHESIS: The goal of this study was to assess the impact of dizziness handicap, illness intrusiveness (in relation to vertigo, tinnitus, and hearing problems), and illness uncertainty on depression in people with the symptoms of Ménière's disease. BACKGROUND: Ménière's disease is a progressive disease of the inner ear, the symptoms of which are vertigo, tinnitus, hearing loss, and aural fullness. Although pharmacologic treatments may reduce acute vertigo spells and dizziness, they rarely disappear entirely. Previous research shows that Ménière's disease is unpredictable and has a negative impact on patients' quality of life. METHODS: Questionnaires measuring Dizziness Handicap, Illness Intrusiveness, Illness Uncertainty, and Depression were completed by 74 people with self-reported symptoms of Ménière's disease. Bivariate correlations, repeated-measures analysis of variance, and multiple regression analyses were used to assess the contribution of dizziness handicap, illness intrusiveness, and illness uncertainty to depression. CONCLUSION: Vertigo was more intrusive than tinnitus, hearing problems, and most other comparator illnesses. The intrusiveness of the symptoms of Ménière's disease accounted for 32% of the variance in depression scores, which were high; illness uncertainty did not account for additional variance. Dizziness handicap accounted for 31% of the variation in depression. Although the symptoms of Ménière's disease may not be alleviated by psychological methods, programs that target cognitions in relation to the embarrassment in front of others, and the feeling of being handicapped, may lessen the psychosocial impact of the symptoms of Ménière's disease, which may reduce some of the depression felt in this group.
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Depresión/psicología , Mareo/psicología , Enfermedad de Meniere/psicología , Incertidumbre , Adulto , Anciano , Anciano de 80 o más Años , Depresión/fisiopatología , Evaluación de la Discapacidad , Mareo/fisiopatología , Femenino , Humanos , Masculino , Enfermedad de Meniere/fisiopatología , Persona de Mediana Edad , Calidad de Vida/psicología , Autoinforme , Índice de Severidad de la Enfermedad , Encuestas y CuestionariosRESUMEN
People with chronic fatigue syndrome (CFS) have increased rates of depression, anxiety, and illness intrusiveness; they may also suffer from cognitive problems such as retrospective memory (RM) deficits and concentration difficulties that can stem from diminished information-processing capability. We predicted that this diminished capacity may also lead to deficits in other cognitive functions, such as prospective memory (ProM). Event-, time-, and activity-based ProM was assessed in 11 women with CFS and 12 healthy women using a computer-generated virtual environment (VE). RM was assessed using a free-recall test, and subjective assessment of both ProM and RM was assessed by questionnaire. Groups were equivalent in age and measures of IQ. People with CFS performed slightly worse than healthy controls on both the event- and time-based ProM measures, although these were not statistically significant. However, the CFS group performed significantly worse than the healthy controls on both the free recall-task and on subjective assessment of both RM and ProM. Women with CFS do have some subtle decrements in memory, particularly RM. However, it is possible that the decrements found in the present sample would be greater in real life. Further studies utilizing both healthy controls and illness controls are now needed to ascertain how sensitive the VE measure is and to inform the development of tasks in the VE that place progressively increasing demands on working memory capacity.
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Síndrome de Fatiga Crónica/psicología , Trastornos de la Memoria/complicaciones , Recuerdo Mental , Retención en Psicología , Autoevaluación (Psicología) , Adulto , Análisis de Varianza , Estudios de Casos y Controles , Simulación por Computador , Síndrome de Fatiga Crónica/complicaciones , Síndrome de Fatiga Crónica/fisiopatología , Femenino , Humanos , Intención , Aprendizaje , Análisis por Apareamiento , Trastornos de la Memoria/fisiopatología , Trastornos de la Memoria/psicología , Persona de Mediana Edad , Proyectos Piloto , Valores de Referencia , Conducta Espacial , Interfaz Usuario-ComputadorRESUMEN
Research suggests that the deficits characterizing dyslexia may also be associated with superior visuospatial abilities. Other research suggests that superior visuospatial abilities of people with dyslexia may not have been so far identified because of the lack of appropriate tests of real-life spatial ability. A recent small-scale study found that visuospatial superiority was evident in men with dyslexia. This study assessed the visuospatial ability of adolescents with dyslexia in order to determine whether these adolescents performed better on a pseudo real-life visuospatial test than did their nondyslexic peers. Forty-two adolescents took part in the study. There was an equal numerical split between the experimental and control groups. The experimental group all had a diagnosis of dyslexia by an educational psychologist or specialist teacher. Visuospatial ability was assessed using the Recall of Designs and the Pattern Construction subtests from the British Ability Scales (2nd edition; BAS-11) together with a computer-generated virtual environment test. The assessments were administered in a counterbalanced order. Adolescents with dyslexia tended to perform less well than their nondyslexic peers on the BAS-11 tests; however, this difference was not statistically significant. For the computer-generated virtual environment test (pseudo real-life measure), statistically significant higher scores were achieved by the dyslexic group. These findings suggest that adolescents with dyslexia may exhibit superior visuospatial strengths on certain pseudo real-life tests of spatial ability. The usefulness of these findings is discussed in relation to possible implications for assessment and educational intervention programs for adolescents with dyslexia.
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Aptitud , Dislexia/diagnóstico , Orientación , Desempeño Psicomotor , Percepción Espacial , Interfaz Usuario-Computador , Adolescente , Niño , Dislexia/psicología , Educación Especial , Femenino , Humanos , Masculino , Recuerdo Mental , Pruebas Neuropsicológicas/estadística & datos numéricos , Reconocimiento Visual de Modelos , Psicometría , Medio SocialRESUMEN
BACKGROUND: Many chronic illnesses are accompanied by impaired cognitive functioning. In people with Inflammatory Bowel Disease (IBD), there is some research to suggest a decrement in verbal IQ (VIQ), when compared to people with Irritable Bowel Syndrome (IBS) and healthy controls. Although this is an important finding, it is necessary to ensure that such deficits are not due to methodological problems such as the failure to take into account pre-morbid functioning. METHODS: A total of 88 people (IBD, N = 29; IBS, N = 29; Controls, N = 30) completed the Wechsler Abbreviated Scale of Intelligence (WASI), the Wechsler Test of Adult Reading (WATR), the Trait Rumination Questionnaire (TRQ), the Center for Epidemiologic Studies Depression Scale (CES-D), and the General Health Questionnaire (GHQ-12). RESULTS: We found evidence of a VIQ decrement in both IBD and IBS groups when measured against both healthy controls and against their own pre-morbid IQ scores (WTAR-Predicted WAIS-III IQ measures). However, the decrement was larger (and of clinical significance) in the IBD group but not in the IBS group. CONCLUSION: Some tentative evidence is presented which suggests that poor VIQ performance may be due in part to interference from excessive rumination.
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Enfermedades Inflamatorias del Intestino/epidemiología , Enfermedades Inflamatorias del Intestino/psicología , Inteligencia , Síndrome del Colon Irritable/epidemiología , Síndrome del Colon Irritable/psicología , Adulto , Ansiedad/epidemiología , Trastornos del Conocimiento/epidemiología , Depresión/epidemiología , Humanos , Persona de Mediana Edad , Encuestas y Cuestionarios , Conducta Verbal , Escalas de WechslerRESUMEN
Recent research has shown that people with chronic illnesses often experience cognitive deficits, such deficits may be specific to a particular type of illness, reflecting the disease process itself, or they may be deficits that are common across a number of chronic illnesses. Our study investigated whether people with an organic disease (Inflammatory Bowel Disease) show cognitive dysfunction relative to the control group and people with a functional illness (Irritable Bowel Syndrome), and if so, to elucidate the mechanisms by which such dysfunction occurs. A quasi-experimental design using three groups of participants provided scores on IQ, memory, and cognitive flexibility. Differences in absolute scores were slight. However, a noticeable interaction effect was found between group and IQ: The illness groups showed a deficit in verbal IQ relative to both their own performance IQ and to that of the control group's verbal IQ. This verbal deficit cannot be explained by depression, cognitive load, or medication.