1,062 research outputs found

    Sympathetic Skin Response and Boston Questionnaire in Carpal Tunnel Syndrome

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    We aimed to determine relations between the sudomotor efferent nerve fiber function and Boston questionnaire (BQ) in idiopathic carpal tunnel syndrome (CTS). Median nerve-induced sympathetic skin responses (SSRs) evoked by wrist stimulation were recorded in 108 CTS patients and compared with those in 88 healthy volunteers. The Boston questionnaire form (BQF) was applied to the subjects. All patients and healthy individuals were questioned about the autonomic symptoms in the hand (red or purple skin coloration, excessive sweating, and feeling cold). The average SSR latencies of the patients with CTS were significantly longer than those in the control group (P < 0.001). Positive significant, while weak, correlations were found between the SSR latency, autonomic symptoms, and total sympathetic system scores. No statistically significant relationship was found between the Boston symptom severity, functional capacity scores, and SSR latency. The latter obtained through wrist stimulation was sensitive to support the sudomotor sympathetic dysfunction in patients with CTS. No relationship between the BQF and SSR can be related to the fact that these indices evaluate different aspects of CTS.Ми намагалися встановити взаємовідносини судомоторної функції еферентного нерва та показників Бостонського опитувальника (BQ) у випадках ідіопатичного синдрому зап’ястного каналу (СЗК). Шкірні симпатичні відповіді (ШСВ) відводилися після стимуляції медіанного нерва на рівні зап’ястка у 108 пацієнтів із діагностованим СЗК; ці характеристики порівнювались із такими у 88 здорових добровольців. Усім суб’єктам пропонували форму BQF. Усі пацієнти та здорові особи опитувалися щодо вегетативних симптомів, які проявлялися на кисті (червоне або пурпурове забарвлення шкіри, надмірне потовиділення та відчуття холоду). Середнє значення латентного періоду ШСВ у пацієнтів із СЗК вірогідно перевищувало таке в контрольній групі (P < 0.001). Істотна позитивна, хоча й слабка, кореляція була виявлена між латентним періодом ШСВ, вегетативними симптомами та бальною загальною оцінкою стану симпатичної системи. Не було встановлено вірогідних відносин між показником тяжкості симптомів (згідно з BQF), оцінкою функціональної здатності та латентним періодом ШСВ. Останній параметр, отриманий при стимуляції на рівні зап’ястка, був чутливим щодо судомоторної симпатичної дисфункції у пацієнтів із цим синдромом. Відсутність зв’язку між оцінками BQF та ШСВ може бути зумовлена тим, що дані показники оцінюють різні аспекти ШСВ

    Reducing Anchor Loss in Micromechanical Extensional Mode Resonators

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    Cataloged from PDF version of article.In this work, we propose a novel method to increase the quality factor of extensional mode micromechanical resonators. The proposed resonator topology is suitable for integration in a silicon-based process to fabricate micromechanical filters and oscillators. It is a half-wavelength-long strip excited longitudinally by electrostatic forces, and it is isolated from the substrate by alternating with bars of a quarter wavelength long. This structure causes a large impedance mismatch between the resonator and the substrate and hence reduces the anchor loss considerably. The performance of the resonator is determined by finite element simulations. We introduce an equivalent electrical circuit to predict the performance of the resonator. The electrical model gives results consistent with the finite element simulations. The proposed resonator is expected to have a very small anchor loss resulting in a very high Q

    Mutualist-Provisioned Resources Impact Vector Competency

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    ABSTRACT Many symbionts supplement their host’s diet with essential nutrients. However, whether these nutrients also enhance parasitism is unknown. In this study, we investigated whether folate (vitamin B9) production by the tsetse fly (Glossina spp.) essential mutualist, Wigglesworthia, aids auxotrophic African trypanosomes in completing their life cycle within this obligate vector. We show that the expression of Wigglesworthia folate biosynthesis genes changes with the progression of trypanosome infection within tsetse. The disruption of Wigglesworthia folate production caused a reduction in the percentage of flies that housed midgut (MG) trypanosome infections. However, decreased folate did not prevent MG trypanosomes from migrating to and establishing an infection in the fly’s salivary glands, thus suggesting that nutrient requirements vary throughout the trypanosome life cycle. We further substantiated that trypanosomes rely on symbiont-generated folate by feeding this vitamin to Glossina brevipalpis, which exhibits low trypanosome vector competency and houses Wigglesworthia incapable of producing folate. Folate-supplemented G. brevipalpis flies were significantly more susceptible to trypanosome infection, further demonstrating that this vitamin facilitates parasite infection establishment. Our cumulative results provide evidence that Wigglesworthia provides a key metabolite (folate) that is “hijacked” by trypanosomes to enhance their infectivity, thus indirectly impacting tsetse species vector competency. Parasite dependence on symbiontderived micronutrients, which likely also occurs in other arthropod vectors, represents a relationship that may be exploited to reduce disease transmission. IMPORTANCE Parasites elicit several physiological changes in their host to enhance transmission. Little is known about the functional association between parasitism and microbiota-provisioned resources typically dedicated to animal hosts and how these goods may be rerouted to optimize parasite development. This study is the first to identify a specific symbiont-generated metabolite that impacts insect vector competence by facilitating parasite establishment and, thus, eventual transmission. Specifically, we demonstrate that the tsetse fly obligate mutualist Wigglesworthia provisions folate (vitamin B9) that pathogenic African trypanosomes exploit in an effort to successfully establish an infection in the vector’s MG. This process is essential for the parasite to complete its life cycle and be transmitted to a new vertebrate host. Disrupting metabolic contributions provided by the microbiota of arthropod disease vectors may fuel future innovative control strategies while also offering minimal nontarget effects

    Adult midgut expressed sequence tags from the tsetse fly Glossina morsitans morsitans and expression analysis of putative immune response genes

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    BACKGROUND: Tsetse flies transmit African trypanosomiasis leading to half a million cases annually. Trypanosomiasis in animals (nagana) remains a massive brake on African agricultural development. While trypanosome biology is widely studied, knowledge of tsetse flies is very limited, particularly at the molecular level. This is a serious impediment to investigations of tsetse-trypanosome interactions. We have undertaken an expressed sequence tag (EST) project on the adult tsetse midgut, the major organ system for establishment and early development of trypanosomes. RESULTS: A total of 21,427 ESTs were produced from the midgut of adult Glossina morsitans morsitans and grouped into 8,876 clusters or singletons potentially representing unique genes. Putative functions were ascribed to 4,035 of these by homology. Of these, a remarkable 3,884 had their most significant matches in the Drosophila protein database. We selected 68 genes with putative immune-related functions, macroarrayed them and determined their expression profiles following bacterial or trypanosome challenge. In both infections many genes are downregulated, suggesting a malaise response in the midgut. Trypanosome and bacterial challenge result in upregulation of different genes, suggesting that different recognition pathways are involved in the two responses. The most notable block of genes upregulated in response to trypanosome challenge are a series of Toll and Imd genes and a series of genes involved in oxidative stress responses. CONCLUSIONS: The project increases the number of known Glossina genes by two orders of magnitude. Identification of putative immunity genes and their preliminary characterization provides a resource for the experimental dissection of tsetse-trypanosome interactions

    Lattice dynamics in magnetic superelastic Ni-Mn-In alloys. Neutron scattering and ultrasonic experiments

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    Neutron scattering and ultrasonic methods have been used to study the lattice dynamics of two single crystals of Ni-Mn-In Heusler alloys close to Ni50_{50}Mn34_{34}In16_{16} magnetic superelastic composition. The paper reports the experimental determination of the low-lying phonon dispersion curves and the elastic constants for this alloy system. We found that the frequencies of the TA2_{2} branch are relatively low and it exhibits a small dip anomaly at a wave number ξ01/3\xi_{0} \approx 1/3, which softens with decreasing temperature. Associated with the softening of this phonon, we also observed the softening of the shear elastic constant C=(C11C12)/2C'=(C_{11}-C_{12})/2. Both temperature softenings are typical for bcc based solids which undergo martensitic transformations and reflect the dynamical instability of the cubic lattice against shearing of {110}\{110\} planes along directions. Additionally, we measured low-lying phonon dispersion branches and elastic constants in applied magnetic fields aimed to characterize the magnetoelastic coupling.Comment: 8 pages, 7 figures. Accepted for publication in the Physical Review

    <i>Trypanosoma brucei rhodesiense</i> transmitted by a single tsetse fly bite in vervet monkeys as a model of human African trypanosomiasis

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    Sleeping sickness is caused by a species of trypanosome blood parasite that is transmitted by tsetse flies. To understand better how infection with this parasite leads to disease, we provide here the most detailed description yet of the course of infection and disease onset in vervet monkeys. One infected tsetse fly was allowed to feed on each host individual, and in all cases infections were successful. The characteristics of infection and disease were similar in all hosts, but the rate of progression varied considerably. Parasites were first detected in the blood 4-10 days after infection, showing that migration of parasites from the site of fly bite was very rapid. Anaemia was a key feature of disease, with a reduction in the numbers and average size of red blood cells and associated decline in numbers of platelets and white blood cells. One to six weeks after infection, parasites were observed in the cerebrospinal fluid (CSF), indicating that they had moved from the blood into the brain; this was associated with a white cell infiltration. This study shows that fly-transmitted infection in vervets accurately mimics human disease and provides a robust model to understand better how sleeping sickness develops

    Incorporating scale dependence in disease burden estimates:the case of human African trypanosomiasis in Uganda

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    The WHO has established the disability-adjusted life year (DALY) as a metric for measuring the burden of human disease and injury globally. However, most DALY estimates have been calculated as national totals. We mapped spatial variation in the burden of human African trypanosomiasis (HAT) in Uganda for the years 2000-2009. This represents the first geographically delimited estimation of HAT disease burden at the sub-country scale.Disability-adjusted life-year (DALY) totals for HAT were estimated based on modelled age and mortality distributions, mapped using Geographic Information Systems (GIS) software, and summarised by parish and district. While the national total burden of HAT is low relative to other conditions, high-impact districts in Uganda had DALY rates comparable to the national burden rates for major infectious diseases. The calculated average national DALY rate for 2000-2009 was 486.3 DALYs/100 000 persons/year, whereas three districts afflicted by rhodesiense HAT in southeastern Uganda had burden rates above 5000 DALYs/100 000 persons/year, comparable to national GBD 2004 average burden rates for malaria and HIV/AIDS.These results provide updated and improved estimates of HAT burden across Uganda, taking into account sensitivity to under-reporting. Our results highlight the critical importance of spatial scale in disease burden analyses. National aggregations of disease burden have resulted in an implied bias against highly focal diseases for which geographically targeted interventions may be feasible and cost-effective. This has significant implications for the use of DALY estimates to prioritize disease interventions and inform cost-benefit analyses
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