158 research outputs found

    Optic Flow Stimuli in and Near the Visual Field Centre: A Group fMRI Study of Motion Sensitive Regions

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    Motion stimuli in one visual hemifield activate human primary visual areas of the contralateral side, but suppress activity of the corresponding ipsilateral regions. While hemifield motion is rare in everyday life, motion in both hemifields occurs regularly whenever we move. Consequently, during motion primary visual regions should simultaneously receive excitatory and inhibitory inputs. A comparison of primary and higher visual cortex activations induced by bilateral and unilateral motion stimuli is missing up to now. Many motion studies focused on the MT+ complex in the parieto-occipito-temporal cortex. In single human subjects MT+ has been subdivided in area MT, which was activated by motion stimuli in the contralateral visual field, and area MST, which responded to motion in both the contra- and ipsilateral field. In this study we investigated the cortical activation when excitatory and inhibitory inputs interfere with each other in primary visual regions and we present for the first time group results of the MT+ subregions, allowing for comparisons with the group results of other motion processing studies. Using functional magnetic resonance imaging (fMRI), we investigated whole brain activations in a large group of healthy humans by applying optic flow stimuli in and near the visual field centre and performed a second level analysis. Primary visual areas were activated exclusively by motion in the contralateral field but to our surprise not by central flow fields. Inhibitory inputs to primary visual regions appear to cancel simultaneously occurring excitatory inputs during central flow field stimulation. Within MT+ we identified two subregions. Putative area MST (pMST) was activated by ipsi- and contralateral stimulation and located in the anterior part of MT+. The second subregion was located in the more posterior part of MT+ (putative area MT, pMT)

    Threat of an influenza pandemic: family physicians in the front line

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    <p>Abstract</p> <p>Background</p> <p>The chance of an influenza pandemic is real and clinicians should keep themselves informed about the rationale and science behind preventive and therapeutic principles relating to an (impending) influenza pandemic.</p> <p>Discussion</p> <p>Vaccination is considered the best prevention in case of a pandemic threat and first choice to contain the impact of a pandemic. Pending the availability of an effective pandemic vaccine, antivirals are likely the only effective agents for prevention and treatment. When an influenza pandemic is impending, all interventions aim to prevent people becoming infected and to suppress replication and transmission of the virus as much as possible. Antivirals will be prescribed to patients with laboratory confirmed pre-pandemic influenza as well as to their contacts (post-exposure prophylaxis) which may delay development of or even prevent a pandemic. During a manifest influenza pandemic, however, there is large-scale spreading of the influenza virus. Therefore, preventive use of antivirals is less efficient to prevent transmission. Delaying the pandemic is then important in order to prevent exhausting public health resources and disruption of society. Thus, during a manifest pandemic everyone with influenza symptoms should receive antivirals as quickly as possible, regardless of virological confirmation. To ensure optimal effectiveness of antivirals and to minimize development of drug resistant viral strains, the use of antivirals for annual influenza should be restrictive. The crucial position of family physicians during an (impending) influenza pandemic necessitates the development of primary health care guidelines on this topic for all countries.</p> <p>Summary</p> <p>Family physicians will play a key role in assessing and treating victims of a new influenza virus, and in reassuring the worried well. We outline various possible interventions in the event of an impending and a manifest influenza pandemic, such as non-medial measures, prescription of antivirals, and vaccination, and emphasize the need for pandemic influenza preparedness.</p

    Reduced genomic tumor heterogeneity after neoadjuvat chemotherapy is related to favorable outcome in patients with esophageal adenocarcinoma

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    Neoadjuvant chemo(radio)therapy followed by surgery is the standard of care for patients with locally advanced resectable esophageal adenocarcinoma (EAC). There is increasing evidence that drug resistance might be related to genomic heterogeneity. We investigated whether genomic tumor heterogeneity is different after cytotoxic chemotherapy and is associated with EAC patient survival. We used arrayCGH and a quantitative assessment of the whole genome DNA copy number aberration patterns (‘DNA copy number entropy’) to establish the level of genomic tumor heterogeneity in 80 EAC treated with neoadjuvant chemotherapy followed by surgery (CS group) or surgery alone (S group). The association between DNA copy number entropy, clinicopathological variables and survival was investigated. DNA copy number entropy was reduced after chemotherapy, even if there was no morphological evidence of response to therapy (p<0.001). Low DNA copy number entropy was associated with improved survival in the CS group (p=0.011) but not in the S group (p=0.396). Our results suggest that cytotoxic chemotherapy reduces DNA copy number entropy, which might be a more sensitive tumor response marker than changes in the morphological tumor phenotype. The use of DNA copy number entropy in clinical practice will require validation of our results in a prospective study

    Variations in influenza vaccination coverage among the high-risk population in Sweden in 2003/4 and 2004/5: a population survey

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    <p>Abstract</p> <p>Background</p> <p>In Sweden, the vaccination campaign is the individual responsibility of the counties, which results in different arrangements. The aim of this study was to find out whether influenza vaccination coverage rates (VCRs) had increased between 2003/4 and 2004/5 among population at high risk and to find out the influence of personal preferences, demographic characteristics and health care system characteristics on VCRs.</p> <p>Methods</p> <p>An average sample of 2500 persons was interviewed each season (2003/4 and 2004/5). The respondents were asked whether they had had an influenza vaccination, whether they suffered from chronic conditions and the reasons of non-vaccination. For every county the relevant health care system characteristics were collected via a questionnaire sent to the medical officers of communicable diseases.</p> <p>Results</p> <p>No difference in VCR was found between the two seasons. Personal invitations strongly increased the chance of having had a vaccination. For the elderly, the number of different health care professionals in a region involved in administering vaccines decreased this chance.</p> <p>Conclusion</p> <p>Sweden remained below the WHO-recommendations for population at high risk due to disease. To meet the 2010 WHO-recommendation further action may be necessary to increase vaccine uptake. Increasing the number of personal invitations and restricting the number of different administrators responsible for vaccination may be effective in increasing VCRs among the elderly.</p

    The Human Connectome Project's neuroimaging approach

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    Noninvasive human neuroimaging has yielded many discoveries about the brain. Numerous methodological advances have also occurred, though inertia has slowed their adoption. This paper presents an integrated approach to data acquisition, analysis and sharing that builds upon recent advances, particularly from the Human Connectome Project (HCP). The 'HCP-style' paradigm has seven core tenets: (i) collect multimodal imaging data from many subjects; (ii) acquire data at high spatial and temporal resolution; (iii) preprocess data to minimize distortions, blurring and temporal artifacts; (iv) represent data using the natural geometry of cortical and subcortical structures; (v) accurately align corresponding brain areas across subjects and studies; (vi) analyze data using neurobiologically accurate brain parcellations; and (vii) share published data via user-friendly databases. We illustrate the HCP-style paradigm using existing HCP data sets and provide guidance for future research. Widespread adoption of this paradigm should accelerate progress in understanding the brain in health and disease

    Hormonal crises following receptor radionuclide therapy with the radiolabeled somatostatin analogue [177Lu-DOTA0,Tyr3]octreotate

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    textabstractIntroduction: Receptor radionuclide therapy is a promising treatment modality for patients with neuroendocrine tumors for whom alternative treatments are limited. The aim of this study was to investigate the incidence of hormonal crises after therapy with the radiolabeled somatostatin analogue [177Lu-DOTA0,Tyr3]octreotate (177Lu-octreotate). Materials and methods: All177Lu- octreotate treatments between January 2000 and January 2007 were investigated. Four hundred seventy-six patients with gastroenteropancreatic neuroendocrine tumors and three patients with metastatic pheochromocytoma were included for analysis. Results: Four hundred seventy-nine patients received a total of 1,693 administrations of177Lu-octreotate. Six of 479 patients (1%) developed severe symptoms because of massive release of bioactive substances after the first cycle of177Lu-octreotate. One patient had a metastatic hormone-producing small intestinal carcinoid; two patients had metastatic, hormone-producing bronchial carcinoids; two patients had vasoactive intestinal polypeptide-producing pancreatic endocrine tumors (VIPomas); and one patient had a metastatic pheochromocytoma. With adequate treatment, all patients eventually recovered. Conclusion: Hormonal crises after177Lu- octreotate therapy occur in 1% of patients. Generally,177Lu- octreotate therapy is well tolerated

    Cross-sectional survey of older peoples' views related to influenza vaccine uptake

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    BACKGROUND: The population's views concerning influenza vaccine are important in maintaining high uptake of a vaccine that is required yearly to be effective. Little is also known about the views of the more vulnerable older population over the age of 74 years. METHODS: A cross-sectional survey of community dwelling people aged 75 years and over wh, previous participant was conducted using a postal questionnaire. Responses were analysed by vaccine uptake records and by socio-demographic and medical factors. RESULTS: 85% of men and 75% of women were vaccinated against influenza in the previous year. Over 80% reported being influenced by a recommendation by a health care worker. The most common reason reported for non uptake was good health (44%), or illness considered to be due to the vaccine (25%). An exploration of the crude associations with socio-economic status suggested there may be some differences in the population with these two main reasons. 81% of people reporting good health lived in owner occupied housing with central heating vs. 63% who did not state this as a reason (p = 0.04), whereas people reporting ill health due to the vaccine was associated with poorer social circumstances. 11% lived in the least deprived neighbourhood compared to 36% who did not state this as a reason (p = 0.05) and were less likely to be currently married than those who did not state this as a reason (25% vs 48% p = 0.05). CONCLUSION: Vaccine uptake was high, but non uptake was still noted in 1 in 4 women and 1 in 7 men aged over 74 years. Around 70% reported they would not have the vaccine in the following year. The divergent reasons for non-uptake, and the positive influence from a health care worker, suggests further uptake will require education and encouragement from a health care worker tailored towards the different views for not having influenza vaccination. Non-uptake of influenza vaccine because people viewed themselves as in good health may explain the modest socio-economic differentials in influenza vaccine uptake in elderly people noted elsewhere. Reporting of ill-health due to the vaccine may be associated with a different, poorer background

    Influenza vaccination coverage rates in five European countries during season 2006/07 and trends over six consecutive seasons

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    <p>Abstract</p> <p>Background</p> <p>The objectives of the survey were to identify the level of influenza vaccination coverage in five European countries between 2001 and 2007, to understand the drivers and barriers to vaccination, to assess vaccination intentions for the winter 2007/08 as well as major encouraging factors for vaccination.</p> <p>Methods</p> <p>Between 2001 and 2007, representative household surveys were performed with telephone or mailed (France) interviews of individuals aged 14 and above. The questionnaire used in the UK, Germany, Italy, France and Spain was essentially the same in all seasons. The data were subsequently pooled. Four target groups were defined for the analysis: 1) persons aged 65 years and over; 2) persons working in the medical field; 3) chronically ill persons and 4) combined target group composed of individuals belonging to one or more of the previous groups 1, 2 or 3.</p> <p>Results</p> <p>In 2006/07, vaccination coverage was, 25.0% in UK, 27.4% in Germany, 21.8% in Spain, 24.2% in France and 24.4% in Italy. During six influenza seasons (2001–2007), vaccination coverage showed a slight positive trend in the five countries (p ≤ 0.0001). In the elderly (≥ 65 years), across all countries, no significant trend was seen; the vaccination rate decreased non-significantly from a peak of 64.2% in season 2005/06 to 61.1% in season 2006/07. The most frequent reason for getting vaccinated was a recommendation by the family doctor or nurse (51%), and this was also perceived as the major encouraging factor for vaccination (61%). The main reason for not getting vaccinated was feeling unlikely to catch the flu (36%).</p> <p>Conclusion</p> <p>In the UK, Germany and Spain, influenza vaccination coverage rates in season 2006/07 dropped slightly compared to the previous season. However, a trend of increasing vaccination coverage was observed from 2001/02 to 2006/07 across Europe. The family doctor is the major source of encouragement for individuals getting vaccinated. Efforts to overcome the barriers to vaccination need to be put in place to reach the WHO objective of 75% coverage in the elderly by 2010. This is a major challenge to be faced by governments, healthcare workers and healthcare organisations.</p

    Audiovisual Non-Verbal Dynamic Faces Elicit Converging fMRI and ERP Responses

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    In an everyday social interaction we automatically integrate another’s facial movements and vocalizations, be they linguistic or otherwise. This requires audiovisual integration of a continual barrage of sensory input—a phenomenon previously well-studied with human audiovisual speech, but not with non-verbal vocalizations. Using both fMRI and ERPs, we assessed neural activity to viewing and listening to an animated female face producing non-verbal, human vocalizations (i.e. coughing, sneezing) under audio-only (AUD), visual-only (VIS) and audiovisual (AV) stimulus conditions, alternating with Rest (R). Underadditive effects occurred in regions dominant for sensory processing, which showed AV activation greater than the dominant modality alone. Right posterior temporal and parietal regions showed an AV maximum in which AV activation was greater than either modality alone, but not greater than the sum of the unisensory conditions. Other frontal and parietal regions showed Common-activation in which AV activation was the same as one or both unisensory conditions. ERP data showed an early superadditive effect (AV > AUD + VIS, no rest), mid-range underadditive effects for auditory N140 and face-sensitive N170, and late AV maximum and common-activation effects. Based on convergence between fMRI and ERP data, we propose a mechanism where a multisensory stimulus may be signaled or facilitated as early as 60 ms and facilitated in sensory-specific regions by increasing processing speed (at N170) and efficiency (decreasing amplitude in auditory and face-sensitive cortical activation and ERPs). Finally, higher-order processes are also altered, but in a more complex fashion
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