441 research outputs found

    Speculations on the clinical significance of asymptomatic viral infections

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    A detailed understanding of asymptomatic chronic viral infections is critical to analyse their pathogenesis, assess the severity and burden of disease and, where required, optimize public health control measures. Recent studies on herpesviruses showed that the hostevirus interactions are modulated by coinfections, emphasizing the relevance of co-infections in determining the clinical expression (from asymptomatic to symptomatic infections) and the severity of herpesvirus-associated diseases (either neoplastic or infectious diseases). To demonstrate causality between viruses (virome) and diseases, Koch's postulates should be adapted adding new knowledge on hostemicrobe relationship and microbial interactions. In the present review we aim to provide an update on asymptomatic chronic infections and criteria for causality and on the virological, immunological and hostevirus interactions in asymptomatic chronic infections in human hosts, focusing on herpetic infections

    Integrating seasonal spatiotemporal interspecies and habitat dynamics to identify and hindcast bycatch hotspots of the yellowtail flounder fishery on the Grand Bank

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    A long-standing problem in commercial fisheries is the incidental catch of species that are not targeted by the fishery, called bycatch. Bycatch inflicts unnecessary mortalities and potential economic loss. An economically important fishery with bycatch is the commercial yellowtail flounder bottom trawl fishery on the Grand Bank of Newfoundland. My thesis aims to mitigate bycatch in the yellowtail flounder fishery by using novel spatiotemporal models to identify dynamic bycatch hotspots. In my first chapter, I provide an overview of the yellowtail flounder fishery. In my second chapter, I run seasonal multispecies spatiotemporal models to estimate interspecies bycatch relationships using habitat variables. In my third chapter I perform short term retrospective forecasts of these models to estimate bycatch hotspots relationships. By understanding the spatiotemporal dynamics of interspecies relationships with dynamic habitat covariates, and developing a retrospective forecast model, I provide a framework for future bycatch mitigation strategies to contribute to the sustainability and economic efficiency of this fishery

    Frequent detection of high human papillomavirus DNA loads in oral potentially malignant disorders

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    Human papillomavirus (HPV) is estimated to be the cause of 40-80% of the squamous cell carcinoma of the oropharynx but only of a small fraction of the oral cavity cancers. The prevalence of oral HPV infection has significantly increased in the last decade, raising concerns about the HPV role in progression of oral potentially malignant disorders (OPMD) toward squamous cell carcinomas. We sought to study HPV infection in patients with oral lesions, and in control individuals, using non-invasive and site-specific oral brushing and sensitive molecular methods. HPV DNA positivity and viral loads were evaluated in relation to patient data and clinical diagnosis. We enrolled 116 individuals attending Dental Clinics: 62 patients with benign oral lesions (e.g. fibromas, papillomatosis, ulcers) or OPMD (e.g. lichen, leukoplakia) and 54 controls. Oral cells were collected with Cytobrush and HPV-DNA detected with quantitative real-time PCR (qPCR) for the more common high-risk (HR) and low-risk (LR) genotypes. HPV detection rate, percentage of HR HPVs and HPV-DNA loads (namely HPV16 and in particular, HPV18) were significantly higher in patients than in controls. Lichen planus cases had the highest HPV positive rate (75.0%), hairy leukoplakia the lowest (33.3%). This study detected unexpectedly high rates of HPV infection in cells of the oral mucosa. The elevated HR HPV loads found in OPMD suggest the effectiveness of qPCR in testing oral lesions. Prospective studies are needed to establish whether elevated viral loads represent a clinically useful marker of the risk of malignant progression

    Speech and non‐speech processing in children with phonological disorders: an electrophysiological study

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    OBJECTIVE: To determine whether neurophysiological auditory brainstem responses to clicks and repeated speech stimuli differ between typically developing children and children with phonological disorders. INTRODUCTION: Phonological disorders are language impairments resulting from inadequate use of adult phonological language rules and are among the most common speech and language disorders in children (prevalence: 8 - 9%). Our hypothesis is that children with phonological disorders have basic differences in the way that their brains encode acoustic signals at brainstem level when compared to normal counterparts. METHODS: We recorded click and speech evoked auditory brainstem responses in 18 typically developing children (control group) and in 18 children who were clinically diagnosed with phonological disorders (research group). The age range of the children was from 7-11 years. RESULTS: The research group exhibited significantly longer latency responses to click stimuli (waves I, III and V) and speech stimuli (waves V and A) when compared to the control group. DISCUSSION: These results suggest that the abnormal encoding of speech sounds may be a biological marker of phonological disorders. However, these results cannot define the biological origins of phonological problems. We also observed that speech-evoked auditory brainstem responses had a higher specificity/sensitivity for identifying phonological disorders than click-evoked auditory brainstem responses. CONCLUSIONS: Early stages of the auditory pathway processing of an acoustic stimulus are not similar in typically developing children and those with phonological disorders. These findings suggest that there are brainstem auditory pathway abnormalities in children with phonological disorders

    Study of suppression effect in the brainstem auditory evoked potential

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    TEMA: o efeito de supressão com ruído branco contralateral verificado sobre o potencial evocado auditivo de tronco encefálico pode ter influência do sistema auditivo eferente. OBJETIVOS: avaliar o efeito de supressão com ruído branco contralateral no potencial evocado auditivo de tronco encefálico em indivíduos com limiares auditivos dentro da normalidade. MÉTODOS: participaram desta pesquisa 25 indivíduos, de 18 a 30 anos de idade, de ambos os sexos, que foram submetidos à anamnese, inspeção do meato acústico externo, audiometria tonal liminar, logoaudiometria e medidas de imitância acústica, com o objetivo de selecionar os indivíduos com acuidade auditiva normal. Em seguida os indivíduos selecionados realizaram o potencial evocado auditivo de tronco encefálico sem e com ruído branco contralateral. RESULTADOS: na comparação entre as condições sem e com ruído branco contralateral verificou-se diferença estatisticamente significante para a amplitude da onda I e para as latências absolutas das ondas III e V, porém não foi observada diferença estatisticamente significante com relação às latências interpicos. CONCLUSÕES: o presente estudo verificou aumento nas latências e diminuição nas amplitudes das ondas I, III e V na presença de ruído contralateral, quando comparadas as condições com e sem ruído. Estes resultados sugerem uma possível influência do sistema nervoso auditivo eferente na modulação das respostas do potencial evocado auditivo de tronco encefálico quando se utiliza ruído branco contralateral.BACKGROUND: the suppression effect with contralateral white noise observed in the brainstem auditory evoked potential can be influenced by the efferent auditory system. AIM: to evaluate the suppression effect with contralateral white noise in the Brainstem Auditory Evoked Potential of individuals with normal hearing. METHODS: 25 individuals, ranging in age from 18 to 30 years, of both genders, were submitted to a clinical history questionnaire, inspection of the external auditory canal, conventional audiometry, speech audiometry and acoustic immittance measurements. Only individuals with normal hearing thresholds were selected. The selected individuals underwent brainstem auditory evoked potential testing with and without contralateral white noise. RESULTS: a significant statistical difference was observed between the situations with and without contralateral white noise, for wave I amplitude and waves III and V latencies. No statistical differences were observed for the interpeak latencies. CONCLUSION: the present study indicated increased latencies and reduced amplitudes of waves I, III and V with contralateral noise, when comparing the situations with and without noise. These results suggest a possible influence of the efferent auditory system on the response modulation of Brainstem auditory evoked potential when contralateral white noise is used

    Scion–rootstock interactions influence the growth and behaviour of the grapevine root system in a heavy clay soil

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    Background and Aims Generally, grapevine roots have been less studied than the above‐ground parts of the plant. Here we analyse scion–rootstock interactions in mature vines growing in a heavy clay soil in a climate characterised by severe summer drought to investigate the effect of the scion–rootstock interaction in a suboptimal soil. Methods and Results The rootstocks, 34 Ecole de Montpellier, 140 Ruggeri and 1103 Paulsen, were grafted onto Nerello Mascalese and Nero d'Avola scions and assessed along with self‐rooted vines. Root distribution and root architecture were analysed using the profile wall method at 0, 60 and 120 cm from the row midline. Root density was greatest at a depth between 21 and 60 cm. The cumulative root fraction for root density registered a β value, a numerical quantity that summarises depth distribution, ranging between 0.932 and 0.962. Root number and density were significantly lower for the self‐rooted vines compared to that of the grafted vines. Conclusions The scion genotypes affected most developmental parameters, including the diameter of the root system, the root density at 21–80 cm depth and the ratio of fine roots to coarse roots. Significance of the Study The scion plays an important role in grapevine root growth, development and distribution in a heavy clay soil, although the mechanism remains unclear

    Clostridium difficile outbreak: epidemiological surveillance, infection prevention and control

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    INTRODUCTION: Clostridium difficile infection (CDI) is currently considered the most common cause of health care-associated infections. The aim is to describe the trend of CDI in an Italian hospital and to assess the efficacy of the measures adopted to manage the burden. METHODS: we looked at CDI from 2016 to 2018. The incidence rate of CDIs was calculated as the number of new infected persons per month by the overall length of stay (incidence per 10,000 patient-days). Changes in the CDI rate during the period considered were analysed using a joinpoint regression model. RESULTS: thanks to the monitoring activity it was possible to adopt a new protocol, in order to manage CDI: the CDI episodes decreased from 85 in 2017 to 31 in 2018 (63% decrease). The joinpoint regression model was a useful tool to identify an important decrement during 2017, statistically significant (slope=-15.84; p= 0.012). CONCLUSIONS: reports based on routine laboratory data can accurately measure population burden of CDI with limited surveillance resources. This acitivity can help target prevention programs and evaluate their effect

    Effects of Environmental Enrichment on the Behavior of Octopus vulgaris in a Recirculating Aquaculture System

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    Octopus vulgaris is a commercially valuable species. It is overexploited in the natural environment and is considered to be an innovative species for aquaculture. However, large-scale farming is generally designed only based on economic requirements, disregarding any form of enrichment that induces the natural behavior of aquatic species. Although many studies have shown the influence of environmental enrichment on terrestrial vertebrates, fish, and cephalopod mollusks, information on the effect of environmental enrichment on the body patterns of O. vulgaris is limited. Therefore, in this study, we assessed how different environmental conditions (Basic vs. Enriched) affect sub-adults of O. vulgaris kept in recirculation systems, through qualitative–quantitative studies of the main body patterns and their potential application in the commercial production of this species. The results indicated that octopuses kept in the enriched environment showed several body patterns and gained a significantly higher weight than those kept in the basic environment. The body patterns displayed by the individuals kept in the basic environment were similar to those exhibited under situations of hostility and inter/intra-specific conflict. Hence, the environment of octopuses needs to be enriched, especially for the large-scale production of this species

    A prospective study comparing quantitative Cytomegalovirus (CMV) polymerase chain reaction in plasma and pp65 antigenemia assay in monitoring patients after allogeneic stem cell transplantation

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    BACKGROUND: Low levels of Cytomegalovirus (CMV) viral load are frequently detected following allogeneic stem cell transplantation (SCT) and CMV disease may still develop in some allogeneic SCT patients who have negative pp65-antigenemia (pp65-Ag) or undetectable DNA. Pp65Ag is a sensitive method to diagnose CMV infection. Quantitative CMV-DNA PCR assay in plasma has been proposed to monitor CMV infection in SCT patients. We evaluated the clinical utility of pp65Ag and PCR assay in plasma of SCT recipients. METHODS: In a prospective longitudinal study, 38 consecutive patients at risk of CMV infection (donor and/or recipient CMV seropositive) were weekly monitored for CMV infection by both quantitative CMV-PCR in plasma (COBAS AMPLICOR CMV MONITOR) and pp65 Ag, during the first 100 days after SCT. RESULTS: A total of 534 blood samples were simultaneously analysed for pp65Ag and PCR. Overall, 28/38 patients (74%) had active CMV infection within 100 days from SCT. In 16 patients, CMV was first detected by pp65 Ag alone; in 5 patients by both methods and in 6 by PCR assay alone; one patient had CMV biopsy-proven intestinal disease without pp65Ag and PCR assays positivity before CMV disease. Overall, three patients developed intestinal CMV disease (7.9%): one had negative both pp65Ag and PCR assays before CMV disease, one had disease and concomitant positivity of both methods, while in the remaining patient, only pp65Ag was positive before CMV disease. CONCLUSION: Plasma PCR(COBAS AMPLICOR CMV MONITOR) and pp65Ag assays were effective in detecting CMV infection, however, discordance between both methods were frequently observed. Plasma PCR and pp65Ag assays may be complementary for diagnosis and management of CMV infection
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