1,031 research outputs found

    Tongue acceleration in humans evoked with intramuscular electrical stimulation of genioglossus

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    Genioglossus was stimulated intramuscularly to determine the effect of regional activation of the muscle on tongue movement in eight healthy adults. Stimulation at motor threshold was delivered with a needle electrode inserted to different depths in the anterior and posterior regions of genioglossus. The current amplitude that induced muscle contraction was ∼80% higher for anterior than posterior sites. Evoked tongue movements were determined from stimulus-triggered averages (150 pulses) of the outputs from an accelerometer fixed to the posterosuperior surface of the tongue. The median amplitude [95% confidence intervals] for the resultant acceleration was 0.0 m/s2 [0.0, 0.2] for anterior and 0.6 m/s2 [0.1, 2.8] for posterior sites. There was a positive relationship between acceleration amplitude and stimulation depth in the posterior of genioglossus (p < 0.001), but acceleration amplitude did not vary with stimulation depth in the anterior region (p = 0.83). This heterogeneity in acceleration responses between muscle regions may contribute to differences in collapsibility of the upper airway

    Chronic breathlessness and sleep problems: a population-based survey

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    ObjectivesThis study aimed to explore the relationship (presence and severity) between chronic breathlessness and sleep problems, independently of diagnoses and health service contact by surveying a large, representative sample of the general population.SettingAnalysis of the 2017 South Australian Health Omnibus Survey, an annual, cross-sectional, face-to-face, multistage, clustered area systematic sampling survey carried out in Spring 2017.Chronic breathlessness was self-reported using the ordinal modified Medical Research Council (mMRC; scores 0 (none) to 4 (housebound)) where breathlessness has been present for more than 3 of the previous 6 months. 'Sleep problems-ever' and 'sleep problem-current' were assessed dichotomously. Regression models were adjusted for age; sex and body mass index (BMI).Results2900 responses were available (mean age 48.2 years (SD=18.6); 51% were female; mean BMI 27. 1 (SD=5.9)). Prevalence was: 2.7% (n=78) sleep problems-past; 6.8% (n=198) sleep problems-current and breathlessness (mMRC 1-4) was 8.8% (n=254). Respondents with sleep problemspast were more likely to be breathless, older with a higher BMI and sleep problems-present also included a higher likelihood of being female.After adjusting for age, sex and BMI, respondents with chronic breathlessness had 1.9 (95% CI=1.0 to 3.5) times the odds of sleep problems-past and sleep problems-current (adjusted OR=2.3; 95% CI=1.6 to 3.3).ConclusionsThere is a strong association between the two prevalent conditions. Future work will seek to understand if there is a causal relationship using validated sleep assessment tools and whether better managing one condition improves the other

    Epidemiology of atopic dermatitis in adults: Results from an international survey.

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    Background:There are gaps in our knowledge of the prevalence of adult atopicdermatitis (AD).Objective:To estimate the prevalence of AD in adults and by disease severity.Methods:This international, cross-sectional, web-based survey was performed inthe United States, Canada, France, Germany, Italy, Spain, United Kingdom, andJapan. Adult members of online respondent panels were sent a questionnaire forAD identification and severity assessment; demographic quotas ensured populationrepresentativeness for each country. A diagnosis of AD required subjects to be posi-tive on the modified UK Working Party/ISAAC criteriaandself-report of ever hav-ing an AD diagnosis by a physician. The proportion of subjects with AD whoreported being treated for their condition was determined and also used to estimateprevalence. Severity scales were Patient-Oriented SCORAD, Patient-OrientatedEczema Measure, and Patient Global Assessment.Results:Among participants by region, the point prevalence of adult AD in the over-all/treated populations was 4.9%/3.9% in the US, 3.5%/2.6% in Canada, 4.4%/3.5% inthe EU, and 2.1%/1.5% in Japan. The prevalence was generally lower for males vsfemales, and decreased with age. Regional variability was observed within countries.Severity varied by scale and region; however, regardless of the scale or region, propor-tion of subjects reporting severe disease was lower than mild or moderate disease.Conclusions:Prevalence of adult AD ranged from 2.1% to 4.9% across countries.Severe AD represented a small proportion of the overall AD population regardlessof measure or region

    Effect of upper airway fat on tongue dilation during inspiration in awake people with obstructive sleep apnea

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    Study Objectives: To investigate the effect of upper airway fat composition on tongue inspiratory movement and obstructive sleep apnea (OSA). Methods: Participants without or with untreated OSA underwent a 3T magnetic resonance imaging (MRI) scan. Anatomical measurements were obtained from T2-weighted images. Mid-sagittal inspiratory tongue movements were imaged using tagged MRI during wakefulness. Tissue volumes and percentages of fat were quantified using an mDIXON scan. Results: Forty predominantly overweight participants with OSA were compared to 10 predominantly normal weight controls. After adjusting for age, BMI, and gender, the percentage of fat in the tongue was not different between groups (analysis of covariance [ANCOVA], p = 0.45), but apnoeic patients had a greater tongue volume (ANCOVA, p = 0.025). After adjusting for age, BMI, and gender, higher OSA severity was associated with larger whole tongue volume (r = 0.51, p < 0.001), and greater dilatory motion of the anterior horizontal tongue compartment (r = -0.33, p = 0.023), but not with upper airway fat percentage. Higher tongue fat percentage was associated with higher BMI and older age (Spearman r = 0.43, p = 0.002, and r =0.44, p = 0.001, respectively), but not with inspiratory tongue movements. Greater inspiratory tongue movement was associated with larger tongue volume (e.g. horizontal posterior compartment, r = -0.44, p = 0.002) and smaller nasopharyngeal airway (e.g. oblique compartment, r = 0.29, p = 0.040). Conclusions: Larger tongue volume and a smaller nasopharynx are associated with increased inspiratory tongue dilation during wakefulness in people with and without OSA. This compensatory response was not influenced by higher tongue fat content. Whether this is also true in more obese patient populations requires further investigation

    The relationship between mandibular advancement, tongue movement, and treatment outcome in obstructive sleep apnea

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    Study Objectives: To characterize how mandibular advancement enlarges the upper airway via posterior tongue advancement in people with obstructive sleep apnea (OSA) and whether this is associated with mandibular advancement splint (MAS) treatment outcome. Methods: One-hundred and one untreated people with OSA underwent a 3T magnetic resonance (MRI) scan. Dynamic mid-sagittal posterior tongue and mandible movements during passive jaw advancement were measured with tagged MRI. Upper airway cross-sectional areas were measured with the mandible in a neutral position and advanced to 70% of maximum advancement. Treatment outcome was determined after a minimum of 9 weeks of therapy. Results: Seventy-one participants completed the study: 33 were responders (AHI50% AHI reduction), 11 were partial responders (>50% AHI reduction but AHI>10 events/hr), and 27 nonresponders (AHI reduction 4 mm). In comparison, a model using only baseline AHI correctly classified 50.0% of patients (5-fold cross-validated 52.5%, n = 40). Conclusions: Tongue advancement and upper airway enlargement with mandibular advancement in conjunction with baseline AHI improve treatment response categorization to a satisfactory level (69.2%, 5-fold cross-validated 62.5%)

    SCLC extensive disease – treatment guidance by extent or/and biology of response?

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    In extensive disease of small cell lung cancer a doubling of the one-year-survival rate was reported in August 2007 by prophylactic cranial irradiation applied to patients who experienced any response to initial chemotherapy. We discuss the treatment concept of extensive disease in the face of the latest results and older studies with additional thoracic irradiation in this subgroup. A randomized trial with prophylactic cranial irradiation published in 1999 demonstrated an improvement of 5-year-overall-survival for complete responders (at least at distant levels) receiving additional thoracic radiochemotherapy compared to chemotherapy alone (9.1% vs. 3.7%). But, these results were almost neglected and thoracic radiotherapy was not further investigated for good responders of extensive disease. However, in the light of current advances by prophylactic cranial irradiation these findings are noteworthy on all accounts. Considering both, a possible interpretation of these data could be a survival benefit of local control by simultaneous thoracic radiochemotherapy in the case of improved distant control due to chemotherapy and prophylactic cranial irradiation. Furthermore the question arises whether the tumor biology indicated by the response to chemotherapy should be integrated in the present classification

    Cirsium species show disparity in patterns of genetic variation at their range-edge, despite similar patterns of reproduction and isolation

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    Genetic variation was assessed across the UK geographical range of Cirsium acaule and Cirsium heterophyllum. A decline in genetic diversity and increase in population divergence approaching the range edge of these species was predicted based on parallel declines in population density and seed production reported seperately. Patterns were compared with UK populations of the widespread Cirsium arvense.Populations were sampled along a latitudinal transect in the UK and genetic variation assessed using microsatellite markers. Cirsium acaule shows strong isolation by distance, a significant decline in diversity and an increase in divergence among range-edge populations. Geographical structure is also evident in C. arvense, whereas no such patterns are seen in C.heterophyllum. There is a major disparity between patterns of genetic variation in C. acaule and C. heterophyllum despite very similar patterns in seed production and population isolation in these species. This suggests it may be misleading to make assumptions about the geographical structure of genetic variation within species based solely on the present-day reproduction and distribution of populations

    Phylogenetic Codivergence Supports Coevolution of Mimetic Heliconius Butterflies

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    The unpalatable and warning-patterned butterflies _Heliconius erato_ and _Heliconius melpomene_ provide the best studied example of mutualistic M&#xfc;llerian mimicry, thought &#x2013; but rarely demonstrated &#x2013; to promote coevolution. Some of the strongest available evidence for coevolution comes from phylogenetic codivergence, the parallel divergence of ecologically associated lineages. Early evolutionary reconstructions suggested codivergence between mimetic populations of _H. erato_ and _H. melpomene_, and this was initially hailed as the most striking known case of coevolution. However, subsequent molecular phylogenetic analyses found discrepancies in phylogenetic branching patterns and timing (topological and temporal incongruence) that argued against codivergence. We present the first explicit cophylogenetic test of codivergence between mimetic populations of _H. erato_ and _H. melpomene_, and re-examine the timing of these radiations. We find statistically significant topological congruence between multilocus coalescent population phylogenies of _H. erato_ and _H. melpomene_, supporting repeated codivergence of mimetic populations. Divergence time estimates, based on a Bayesian coalescent model, suggest that the evolutionary radiations of _H. erato_ and _H. melpomene_ occurred over the same time period, and are compatible with a series of temporally congruent codivergence events. This evidence supports a history of reciprocal coevolution between M&#xfc;llerian co-mimics characterised by phylogenetic codivergence and parallel phenotypic change

    Evaluation of machine-learning methods for ligand-based virtual screening

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    Machine-learning methods can be used for virtual screening by analysing the structural characteristics of molecules of known (in)activity, and we here discuss the use of kernel discrimination and naive Bayesian classifier (NBC) methods for this purpose. We report a kernel method that allows the processing of molecules represented by binary, integer and real-valued descriptors, and show that it is little different in screening performance from a previously described kernel that had been developed specifically for the analysis of binary fingerprint representations of molecular structure. We then evaluate the performance of an NBC when the training-set contains only a very few active molecules. In such cases, a simpler approach based on group fusion would appear to provide superior screening performance, especially when structurally heterogeneous datasets are to be processed

    Predicting language diversity with complex network

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    Evolution and propagation of the world's languages is a complex phenomenon, driven, to a large extent, by social interactions. Multilingual society can be seen as a system of interacting agents, where the interaction leads to a modification of the language spoken by the individuals. Two people can reach the state of full linguistic compatibility due to the positive interactions, like transfer of loanwords. But, on the other hand, if they speak entirely different languages, they will separate from each other. These simple observations make the network science the most suitable framework to describe and analyze dynamics of language change. Although many mechanisms have been explained, we lack a qualitative description of the scaling behavior for different sizes of a population. Here we address the issue of the language diversity in societies of different sizes, and we show that local interactions are crucial to capture characteristics of the empirical data. We propose a model of social interactions, extending the idea from, that explains the growth of the language diversity with the size of a population of country or society. We argue that high clustering and network disintegration are the most important characteristics of models properly describing empirical data. Furthermore, we cancel the contradiction between previous models and the Solomon Islands case. Our results demonstrate the importance of the topology of the network, and the rewiring mechanism in the process of language change
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