173 research outputs found
Clinical, evolutive aspects and treatment approaches in acute necrotizing ulcerative gingivitis
Rezumat.
Gingivita ulcero‑necrotică Vincent este o afecţiune contagioasă, pro‑
vocată de simbioza dintre fuso‑ spirochete (bacillus fusiformis) şi boreliile
Vincent. Această simbioză, în condiţii normale, reprezintă flora saprofită a
cavităţii bucale, însă în condiţii nefavorabile aceste microorganisme devin
agresive, provocând gingivita ulcero‑necrotică.
Majoritatea gingivitelor ulcero‑necrotice, necesită interpretarea mult
mai subtilă, care se impune în situaţia când se suspectă pe lângă concursul
germenului infectat şi scăderea rezistenţei organismului de hipersensibili‑
tatea lui la diferite substanţe medicamentoase, produse alimentare, etc. În
plus, semnele de manifestare ulcero‑necrotice a unei patologii somatice în
cavitatea orală îmbracă aspecte foarte diverse, dependente de gravitatea de‑
reglărilor generale, de starea sistemului imun al teritoriului bucal, de pato‑
genitatea şi tropismul, adesea imprevizibil al florei microbiene satelite.Summary.
Acute necrotizing ulcerative gingivitis is a contagious disease caused by
the symbiosis of Fuso‑spirochete (Bacillus fusiformis) and boreliile Vin‑
cent. This symbiosis, in normal conditions, is saprophytic flora of the cavity
mouth, but these microorganisms under unfavorable conditions become
aggressive, causing ulcero‑necrotic gingivitis.
Most ulcero‑necrotic gingivitis, requires interpretation more subtle. In
addition, signs ulcero‑necrotic manifestations of somatic diseases in the
oral cavity takes the issues very different, depending on the seriousness of
general disorders, immune system status of the territory of mouth, the pa‑
thogenicity and tropism, often unpredictable satellite of microbial flora
A review: Aedes-borne arboviral infections, controls and Wolbachia-based strategies
Arthropod-borne viruses (Arboviruses) continue to generate significant health and economic burdens for people living in endemic regions. Of these viruses, some of the most important (e.g., dengue, Zika, chikungunya, and yellow fever virus), are transmitted mainly by Aedes mosquitoes. Over the years, viral infection control has targeted vector population reduction and inhibition of arboviral replication and transmission. This control includes the vector control methods which are classified into chemical, environmental, and biological methods. Some of these control methods may be largely experimental (both field and laboratory investigations) or widely practised. Perceptively, one of the biological methods of vector control, in particular, Wolbachia-based control, shows a promising control strategy for eradicating Aedes-borne arboviruses. This can either be through the artificial introduction of Wolbachia, a naturally present bacterium that impedes viral growth in mosquitoes into heterologous Aedes aegypti mosquito vectors (vectors that are not natural hosts of Wolbachia) thereby limiting arboviral transmission or via Aedes albopictus mosquitoes, which naturally harbour Wolbachia infection. These strategies are potentially undermined by the tendency of mosquitoes to lose Wolbachia infection in unfavourable weather conditions (e.g., high temperature) and the inhibitory competitive dynamics among co-circulating Wolbachia strains. The main objective of this review was to critically appraise published articles on vector control strategies and specifically highlight the use of Wolbachia-based control to suppress vector population growth or disrupt viral transmission. We retrieved studies on the control strategies for arboviral transmissions via arthropod vectors and discussed the use of Wolbachia control strategies for eradicating arboviral diseases to identify literature gaps that will be instrumental in developing models to estimate the impact of these control strategies and, in essence, the use of different Wolbachia strains and feature
Neuro-oscillatory tracking of low- and high-level musico-acoustic features during naturalistic music listening: insights from an intracranial electroencephalography study
Studies investigating the neural processing of musico-acoustic features have tended to do so using highly controlled musical stimuli. However, it is increasingly argued that failing to use naturalistic stimuli limits the extent to which findings from lab studies can be extrapolated to rich and varied real-world experiences. Here, we recorded electrical brain activity from 8 epileptic patients, implanted for pre-surgical evaluation with Stereo-encephalography (SEEG), while they listened to pieces from the western tonal music repertoire. We estimated the sound intensity and key and pulse clarity of the stimuli using a toolbox for automatic extraction of musico-acoustic features. We then used partial-correlation analyses to examine the patterns of neuro-oscillatory activity associated with the processing of these features. Our results showed clear tracking of sound intensity in high-gamma and alpha frequency bands in posterior superior temporal gyrus, reflecting neural firing and the transfer of auditory information from the thalamus to auditory cortices, respectively. Patterns of partial correlations, in line with our hypotheses, also suggested limbic and inferior frontal cortical tracking of tonal and rhythmic uncertainty, albeit without the robustness shown for sound intensity tracking in auditory areas. The study provides an important contribution to the existing literature in its adherence to the call for a greater use of ecologically valid stimuli in neuroscientific investigations of music listening. Our results, specifically, have implications for research on the neural processing of musical uncertainty and for future studies seeking to use intracranial EEG to examine naturalistic music processing
Adults see vision to be more informative than it is
Humans gain a wide range of knowledge through interacting with the environment. Each aspect of our perceptual experiences offers a unique source of information about the world—colours are seen, sounds heard and textures felt. Understanding how perceptual input provides a basis for knowledge is thus central to understanding one's own and others' epistemic states. Developmental research suggests that 5-year-olds have an immature understanding of knowledge sources and that they overestimate the knowledge to be gained from looking. Without evidence from adults, it is not clear whether the mature reasoning system outgrows this overestimation. The current study is the first to investigate whether an overestimation of the knowledge to be gained from vision occurs in adults. Novel response time paradigms were adapted from developmental studies. In two experiments, participants judged whether an object or feature could be identified by performing a specific action. Adult participants found it disproportionately easy to accept looking as a proposed action when it was informative, and difficult to reject looking when it was not informative. This suggests that adults, like children, overestimate the informativeness of vision. The origin of this overestimation and the implications that the current findings bear on the interpretation of children's overestimation are discussed
Efficacy of flukicides against Fasciola hepatica and first report of triclabendazole resistance on German sheep farms
Fasciola hepatica infections lead to severe health problems and production losses in sheep farming, if not treated effectively. Triclabendazole has been used extensively over decades due to its unique efficacy range against all definitive hostfluke stages but published data about the susceptibility of F. hepatica to anthelmintics in Germany are lacking. This study aimed to identify current F. hepatica infections in German sheep flocks by coproscopic examinations and to evaluate the efficacy of anthelmintics with a focus on triclabendazole in a field study conducted from 2020 to 2022. Initial screening included 71 sheep farms, many of them with known history of fasciolosis. In this highly biased sample set, the frequency of F. hepatica infection at individual sheep and farm level were 12.8% and 35.2%, respectively. Additionally, eggs of Paramphistominae were found at frequencies of 4.8% and 15.5% at individual sheep and farm level, respectively. Due to low egg shedding intensity, faecal egg count reduction (FECR) tests could only be conducted on a few farms. The efficacy of triclabendazole was tested on 11 farms and albendazole on one farm, including 3–53 sheep/farm. Individual faecal samples were collected before and two weeks after treatment to evaluate the FECR using the sedimentation or FLUKEFINDER® or a modified FLUKEFINDER® method. On all farms a coproantigen reduction test was conducted in parallel. Lacking efficacy of triclabendazole even at double dosage was shown on one farm associated with a high number of animal losses due to acute fasciolosis. On this farm, the Fasciola miracidium development test was additionally performed, revealing a high in vitro ovicidal activity of albendazole while closantel was effective in vivo. On all other farms, sufficient efficacy of triclabendazole was observed. In conclusion, triclabendazole resistance appears not to be widespread on German sheep farms but, when present, can have serious effects on animal health
Intracranial recordings and computational modelling of music reveal the time course of prediction error signaling in frontal and temporal cortices
Prediction is held to be a fundamental process underpinning perception, action and cognition. To examine the time-course of prediction error signaling, we recorded intracranial EEG activity from 9 pre-surgical epileptic patients while they listened to melodies whose information-theoretic predictability had been characterized using a computational model. We examined oscillatory activity in the superior temporal gyrus (STG), the middle temporal gyrus (MTG) and the pars orbitalis of the inferior frontal gyrus (IFG), lateral cortical areas previously implicated in auditory predictive processing. We also examined activity in anterior cingulate gyrus (ACG), the insula and amygdala, to determine whether signatures of prediction error signaling may also be observable in these subcortical areas. Our results demonstrate that the information content (a measure of unexpectedness) of musical notes modulates the amplitude of low-frequency oscillatory activity (theta to beta power) in bilateral STG and right MTG from within 100 and 200ms of note-onset respectively. Our results also show this cortical activity to be accompanied by low-frequency oscillatory modulation in ACG and insula - areas previously associated with mediating physiological arousal. Finally, we showed that modulation of low-frequency activity is followed by that of high-frequency (gamma) power from approximately 200ms in the STG, between 300ms and 400ms in the left insula and between 400 and 500ms in the ACG. We discuss these results with respect to models of neural processing that emphasize gamma activity as an index of prediction error signaling, and highlight the usefulness of musical stimuli in revealing the wide-reaching neural consequences of predictive processing
An intracranial EEG study of the neural dynamics of musical valence processing
The processing of valence is known to recruit the amygdala, orbitofrontal cortex and relevant sensory areas. However, how these regions interact remains unclear. We recorded cortical electrical activity from 7 epileptic patients implanted with depth electrodes for presurgical evaluation while they listened to positively and negatively valenced musical chords. Time frequency analysis suggested a specific role of the orbitofrontal cortex in the processing of positively valenced stimuli while, most importantly, Granger causality analysis revealed that the amygdala tends to drive both the orbitofrontal cortex and the auditory cortex in theta and alpha frequency bands, during the processing of valenced stimuli. Results from the current study show the amygdala to be a critical hub in the emotion processing network: specifically one that influences not only the higher order areas involved in the evaluation of the stimulus’s emotional value but also the sensory cortical areas involved in the processing of its low level acoustic features
Effects of infection history on dengue virus infection and pathogenicity
The understanding of immunological interactions among the four dengue virus (DENV)
serotypes and their epidemiological implications is often hampered by the lack of individuallevel infection history. Using a statistical framework that infers full infection history, we
analyze a prospective pediatric cohort in Nicaragua to characterize how infection history
modulates the risks of DENV infection and subsequent clinical disease. After controlling for
age, one prior infection is associated with 54% lower, while two or more are associated with
91% higher, risk of a new infection, compared to DENV-naive children. Children >8 years old
have 55% and 120% higher risks of infection and subsequent disease, respectively, than their
younger peers. Among children with ≥1 prior infection, intermediate antibody titers increase,
whereas high titers lower, the risk of subsequent infection, compared with undetectable
titers. Such complex dependency needs to be considered in the design of dengue vaccines
and vaccination strategies
Recreating blood-brain barrier physiology and structure on chip: A novel neurovascular microfluidic bioreactor
The blood-brain barrier (BBB) is a critical structure that serves as the gatekeeper between the central nervous system and the rest of the body. It is the responsibility of the BBB to facilitate the entry of required nutrients into the brain and to exclude potentially harmful compounds; however, this complex structure has remained difficult to model faithfully in vitro. Accurate in vitro models are necessary for understanding how the BBB forms and functions, as well as for evaluating drug and toxin penetration across the barrier. Many previous models have failed to support all the cell types involved in the BBB formation and/or lacked the flow-created shear forces needed for mature tight junction formation. To address these issues and to help establish a more faithful in vitro model of the BBB, we have designed and fabricated a microfluidic device that is comprised of both a vascular chamber and a brain chamber separated by a porous membrane. This design allows for cell-to-cell communication between endothelial cells, astrocytes, and pericytes and independent perfusion of both compartments separated by the membrane. This NeuroVascular Unit (NVU) represents approximately one-millionth of the human brain, and hence, has sufficient cell mass to support a breadth of analytical measurements. The NVU has been validated with both fluorescein isothiocyanate (FITC)-dextran diffusion and transendothelial electrical resistance. The NVU has enabled in vitro modeling of the BBB using all human cell types and sampling effluent from both sides of the barrier
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