Publication date: Available online 8 May 2017
Source:Biochimica et Biophysica Acta (BBA) - Gene Regulatory Mechanisms
Author(s): Mads Bengtsen, Linda Sørensen, Linn Aabel, Marit Ledsaak, Vilborg Matre, Odd Stokke Gabrielsen
LIM-domain proteins, containing multiple cysteine-rich zinc finger-like motifs, have been shown to play diverse roles in several cellular processes. A common theme is that they mediate important protein-protein interactions that are key to their function. Androgen receptor-associated protein 55 (ARA55) belongs to this family of bridging proteins containing four C-terminal LIM domains. It has a dual role with functions both at focal adhesions and in the nucleus, apparently shuttling between the two compartments. In the present work, we have expanded our understanding of its nuclear functions by showing that it interacts with three nuclear regulators not previously linked to ARA55. We first identified ARA55 as a novel interaction partner of the nuclear kinase HIPK1 and found that ARA55, like HIPK1, also interacts with the transcription factor c-Myb. In search of a function for these associations, we observed that the coactivator p300 not only binds to c-Myb, but to ARA55 as well. When combined, c-Myb, p300, HIPK1 and ARA55 caused strong synergistic activation of a chromatinized reporter gene. In parallel, all partners, including p300, were efficiently recruited to chromatin at the c-Myb-bound promoter. Consistent with this cooperation, we found that c-Myb and ARA55 share a common set of target genes in an osteosarcoma cellular context. We propose that ARA55 and HIPK1 assist c-Myb in recruiting the coactivator and acetyltransferase p300 to chromatin.
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Δευτέρα 8 Μαΐου 2017
The adaptor protein ARA55 and the nuclear kinase HIPK1 assist c-Myb in recruiting p300 to chromatin
I strongly recommend that all practicing physicians consider such a list, and review it occasionally. I wish for the judgement to know what is best for my patients and to weigh the merits of interventions; surgically, medically, and radiotherapeutically. I wish that I can master the complexities of the practice of medicine and be worthwhile as a physician. I wish for the honesty and integrity to objectively assess my competencies and fallibilities. I wish for the intellectual drive to maintain currency of knowledge. I wish for the wisdom to assess and maintain appropriate costs for medical care. I wish for the integrity to avoid marketing my skills and accomplishments unrealistically and erroneously. I wish for the compassion that allows me to separate my personal problems from the needs of the patients that I serve. I wish for the courage to challenge the wisdom of those that create policies and regulations that fail to consider the full dimension and scope of medical care. Please p
Anapafseos 5 . Agios Nikolaos
Crete.Greece.72100
2841026182
Preparation and characterization of tunable oil-encapsulated alginate microfibers
Publication date: 15 August 2017
Source:Materials & Design, Volume 128
Author(s): A.S. Chaurasia, F. Jahanzad, S. Sajjadi
A single-step microfluidic approach was developed which allowed a wide range of oil-loaded calcium-alginate microfibers to be fabricated at the same compositions but with different morphologies. A framework for characterization of wavy fibers was developed which linked the fiber morphology and tensile strength to the encapsulation type and geometry. The geometry of oil encapsulates as well as the fibers surface morphology were conveniently tuned via the gelation reaction dynamics and phase flow rates. A 2D mathematical reconstruction of the fiber's surface revealed that fibers having spherical and ellipsoid encapsulates enjoyed the highest surface roughness. Tubular fibers endured the highest tensile force before failure, compared to fibers with other encapsulate geometries at a fixed alginate phase ratio (ϕalg). Fibers with increased ϕalg withstood a higher tensile force. However, the strength of fibers reduced if the increase in ϕalg altered the encapsulate geometry from tubular to discrete oil segments. Tubular fibers also underwent maximum elastic and plastic deformation prior to failure, among all fibers.
Graphical abstract
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Direct measurement of residual strains in CFRP-tungsten hybrids using embedded strain gauges
Publication date: 5 August 2017
Source:Materials & Design, Volume 127
Author(s): M. Kanerva, P. Antunes, E. Sarlin, O. Orell, J. Jokinen, M. Wallin, T. Brander, J. Vuorinen
In this work, the implementation of fully embedded electrical resistance strain gauges was studied for a hybrid material system. The samples were laminated using carbon-fiber-reinforced plastic (CFRP) and tungsten. The raw materials and the adhesive used for bonding strain sensors were characterized to understand the overlapping sources of non-linearity and error. Test-specific correction functions for a thermal output were determined for the strain gauge measurement and comparative fiber Bragg grating (FBG) measurement. The strain accumulation in the fiber direction during the cool-down phase for different cure cycles was analyzed using a finite element simulation. According to the results, embedded electrical resistance strain gauges can be used to determine the thermal expansion of a hybrid laminate with acceptable accuracy when thermal output is compensated for using case-specific correction functions accounting for measurement setup, the stiffness of the gauge bonding adhesive, and embedding.
Graphical abstract
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Mechanical performance of piezoelectric fiber composites and electroelastic field concentration near the electrode edges
Publication date: 15 August 2017
Source:Materials & Design, Volume 128
Author(s): Xi Yuan, Song Zhu, Xianfang Li, Chao Chen, Kechao Zhou, Dou Zhang
As important smart materials, piezoelectric fiber composites (PFCs) have shown excellent performance in many areas. However, the electric field strength concentration at the edge of the interdigital electrode may lead to crack propagation and eventual actuating failure of PFCs. In this paper, a novel analytical solution on the electroelastic response of PFCs is proposed to characterize the mechanical performance and obtain optimal structure parameters. The problem is converted to a singular integral equation with logarithmic kernel. By solving the resulting equation, the distributions of electric potential, electric displacement, electric field strength, and strain of PFCs fiber are obtained. The finite element method (FEM) is employed to confirm the results. The results demonstrate that the electric displacement and strain of PFCs are dramatically affected by the permittivity properties and piezoelectric constant of materials. The PFCs made by PZT-5H have higher surface electric displacement than PZT-5A and PZT-4. For a ratio of W/L=1/4, both the electric field and strain obtained the minimal value at the electrode edges, which is better for the mechanical performance of PFCs. Moreover, when the thickness of fibers decreases, the actuating performance of PFCs improves and the probability of fracture failure lessens.
Graphical abstract
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Regional anaesthesia for ophthalmic surgery
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Acute respiratory distress syndrome
<span class="paragraphSection"><div class="boxedTextSection">Key points<ul><li class="bullet">Acute respiratory distress syndrome (ARDS) is commonly encountered in the critical care population and is associated with a high mortality of between 27% and 45%.</li><li class="bullet">ARDS is diagnosed according to the Berlin definition and is characterized as mild, moderate, or severe depending on the <span style="font-style:italic;">P</span>a<span style="text-transform:lowercase;font-variant:small-caps;">O</span><sub>2</sub>/<span style="font-style:italic;">FI</span><span style="text-transform:lowercase;font-variant:small-caps;">O</span><sub>2</sub> ratio.</li><li class="bullet">Accepted management strategies include lung protective ventilation with tidal volumes limited to 6 ml kg<sup>−</sup><sup>1</sup>, positive end expiratory pressure increasing in line with oxygen requirement, and prone positioning in severe cases.</li><li class="bullet">Steroids, statins, inhaled nitric oxide, and high-frequency oscillation ventilation do not have a role in the routine management of adults with ARDS.</li><li class="bullet">Adverse functional and neuropsychological outcomes are increasingly recognized in long-term ARDS survivors.</li></ul></div></span>
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Streptococcus mutans membrane lipid composition: Virulence factors and structural parameters
Publication date: September 2017
Source:Archives of Oral Biology, Volume 81
Author(s): M.A. Bojanich, R.O. Calderón
ObjectiveThe aim of the present work was to analyze whether the location of the dental biofilm was associated with shifts in the membrane fatty acid profile, and whether such shifts could affect certain virulence factors of strains of Streptococcus mutans.DesignAn experimental study was conducted to assess the behavior of S. mutans strains isolated from dental biofilm collected from sound and carious smooth and occlusal surfaces of the oral cavity of children. The lipid composition of the bacterial membrane, structural membrane parameters, acid survival, and ATPase activity were tested at pH 7 and 5.ResultsAt pH 5, an increase in both the unsaturated and the long chain fatty acids as well as in proton ATPase hydrolytic activity was observed in strains isolated from carious smooth surface biofilm but not in carious occlusal surface strains. The observed changes correlated with the studied structural parameters, and were found to be associated with membrane organization. The changes correlated with a decreased in ΔC (sn-1 and sn-2 acyl chain inequivalence), indicative of increased acyl chain interaction.ConclusionsThe obtained results suggest that the acidic environment (pH 5) of smooth surface caries affects membrane organization, inducing a shift in membrane lipid profile, which would likely induce better protein/lipid hydrophobic matching, resulting in increased ATPase activity and higher acid survival.
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A clinical, dermoscopic, and histopathological study of Dermatosis Papulosa Nigra (DPN) – An Indian perspective
Abstract
Background
Dermatosis papulosa nigra (DPN) is a benign cutaneous condition which commonly occurs in dark-skinned people, especially Asians and African Americans. Owing to its benign nature and rarity, very few studies have been conducted to date, and dermoscopic studies are practically nonexistent.
Objectives
To study the clinical and epidemiological characteristics of patients with dermatosis papulosa nigra (DPN) and to correlate the clinical findings with dermoscopic and histopathological findings in DPN.
Methods
A total of 100 patients attending the Dermatology outpatient department at Father Muller Medical College, Mangalore, India, with clinically diagnosed dermatosis papulosa nigra were included in the study. Histopathology and dermoscopic evaluation of the lesions were done, and the characteristics seen were noted.
Results
Earlier onset of lesions was noted in our study, i.e. onset in the 4th decade as compared to the 6th decade in most other studies. A female preponderance, positive family history, history of sun exposure, and involvement of the head and neck were other significant associations. Histopathology revealed an acanthotic variant in all the lesions that were biopsied. The predominant dermoscopic finding was fissures and ridges of the cerebriform pattern followed by comedo-like openings.
Conclusion
Dermatosis papulosa nigra is a benign unaesthetic condition seen in Fitzpatrick skin types IV-VI. The diagnosis is mainly clinical; however, in a few cases histopathology and dermoscopy aid in differentiating it from other benign and malignant tumors. Dermoscopy, in particular, being a noninvasive investigative moiety is a rapid and accurate diagnostic tool.
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Effects of arsenic on adipocyte metabolism: Is arsenic an obesogen?
Publication date: Available online 8 May 2017
Source:Molecular and Cellular Endocrinology
Author(s): Zeltzin A. Ceja-Galicia, Alberto Daniel, Ana María Salazar, Pablo Pánico, Patricia Ostrosky-Wegman, Andrea Díaz-Villaseñor
The environmental obesogen model proposes that in addition to a high-calorie diet and diminished physical activity, other factors such as environmental pollutants and chemicals are involved in the development of obesity. Although arsenic has been recognized as a risk factor for Type 2 Diabetes with a specific mechanism, it is still uncertain whether arsenic is also an obesogen. The impairment of white adipose tissue (WAT) metabolism is crucial in the onset of obesity, and distinct studies have evaluated the effects of arsenic on it, however only in some of them for obesity-related purposes. Thus, the known effects of arsenic on WAT/adipocytes were integrated based on the diverse metabolic and physiological processes that occur in WAT and are altered in obesity, specifically: adipocyte growth, adipokine secretion, lipid metabolism, and glucose metabolism. The currently available information suggests that arsenic can negatively affect WAT metabolism, resulting in arsenic being a potential obesogen.
Graphical abstract
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Crosstalk between STAT5 activation and PI3K/AKT functions in normal and transformed mammary epithelial cells
Source:Molecular and Cellular Endocrinology
Author(s): Patrick D. Rädler, Barbara L. Wehde, Kay-Uwe Wagner
Janus kinases (JAKs) and signal transducers and activators of transcription (STATs) have been shown to function downstream of several peptide hormones and cytokines that are required for postnatal development and secretory function of the mammary gland. As part of an extended network, these signal transducers can engage in crosstalk with other pathways to facilitate synergistic, and sometimes antagonistic, actions of different growth factors. Specifically, signaling through the JAK2/STAT5 cascade has been demonstrated to be indispensable for the specification, proliferation, differentiation, and survival of secretory mammary epithelial cells. Following a concise description of major cellular programs in mammary gland development and the role of growth factors that rely on JAK/STAT signaling to orchestrate these programs, this review highlights the significance of active STAT5 and its crosstalk with the PI3 kinase and AKT1 for mediating the proliferation of alveolar progenitors and survival of their functionally differentiated descendants in the mammary gland. Based on its ability to provide self-sufficiency in growth signals that are also capable of overriding intrinsic cell death programs, persistently active STAT5 can serve as a potent oncoprotein that contributes to the genesis of breast cancer. Recent experimental evidence demonstrated that, similar to normal developmental programs, oncogenic functions of STAT5 rely on molecular crosstalk with PI3K/AKT signaling for the initiation, and in some instances the progression, of breast cancer. The multitude by which STATs can interact with individual mediators of the PI3K/AKT signaling cascade may provide novel avenues for targeting signaling nodes within molecular networks that are crucial for the survival of cancer cells.
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Luminescent properties of heterotrinuclear 3d–4f complexes constructed from a naphthalenediol-based acyclic bis(salamo)-type ligand
Publication date: 5 September 2017
Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 184
Author(s): Wen-Kui Dong, Shan-Shan Zheng, Jin-Tong Zhang, Yang Zhang, Yin-Xia Sun
Heterotrinuclear 3d–4f complexes with a naphthalenediol-based acyclic bis(salamo)-type ligand have been synthesized and structurally characterized. Spectral titrations clearly show that the heterotrinuclear complexes [Zn2(L)La(OAc)3] (1), [Zn2(L)Ce(OAc)3] (2) and [Zn2(L)Dy(OAc)3(CH3OH)]·CH2Cl2 (3) are acquired by the substitution reaction of the obtained homotrinuclear Zn(II) complex with 1 equiv. of Ln(NO3)3 (Ln3+=La3+, Ce3+ and Dy3+). Two Zn(II) ions are penta- and hexa-coordinated with geometries of distorted tetragonal pyramid and octahedron. La(III) ion is deca-coordinated, adopting a distorted bicapped square antiprism geometry. Ce(III) ion is nona-coordinated with geometry of distorted capped square antiprism as well as Dy(III) ion. The different coordination modes of acetate ions in complexes 1, 2 and 3 lead to different coordination numbers of the lanthanide(III) ions. Furthermore, the structures and fluorescence properties have been discussed.
Graphical abstract
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Trace element levels in an area impacted by old mining operations and their relationship with beehive products
Publication date: 1 December 2017
Source:Science of The Total Environment, Volumes 599–600
Author(s): E. Álvarez-Ayuso, P. Abad-Valle
The environmental status of an area impacted by Roman mining activities was assessed in order to establish the current risks posed by such old mine emplacements. For this purpose, soil samples were collected throughout the mining area and analysed for their total, mobile and mobilizable trace element (As, Cd, Mo, Sb and Zn) contents. Additionally, beehive products (honey and pollen) were also sampled and evaluated for their use as environmental indicators of the area. The results obtained were compared with those from a control non-polluted area. The mine soils presented slightly increased levels of Cd and Sb (about 2- to -3-fold their normal soil concentrations), whereas the enrichment of As reached considerable levels, with concentrations almost ten-fold of those considered the threshold for causing toxicity. Leachable As contents exhibited very high values (1.2–21.9mgkg−1), indicating the need for risk attenuation measures. All trace elements were mainly partitioned in the soil residual fraction, especially Mo (76–99%) and Sb (61–91%). Significant partitioning levels were also found in the reducible fraction of As (up to 35%) and Cd (up to 38%), and in the oxidizable fraction of Mo (up to 23%). The reducible pool of As was particularly relevant due to the eventual mobilization of this element under reducing conditions. Among the beehive products tested, honey proved not to be useful as an environmental indicator, whereas pollen showed great potential as an indicator when the contamination levels were moderate to high.
Graphical abstract
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A screen-printed voltammetric electronic tongue for the analysis of complex mixtures of metal ions
Publication date: October 2017
Source:Sensors and Actuators B: Chemical, Volume 250
Author(s): Clara Pérez-Ràfols, Núria Serrano, José Manuel Díaz-Cruz, Cristina Ariño, Miquel Esteban
A voltammetric electronic tongue was constituted by four screen-printed modified electrodes: a carbon nanofiber modified electrode, an ex-situ antimony film electrode prepared from carbon nanofiber modified electrode, and two carbon nanofiber electrodes chemically modified with Cys and GSH. The tongue was successfully applied to the analysis of a complex mixture of metal ions (4 analytes and 2 interferences) by differential pulse anodic stripping voltammetry. Each sensor was firstly studied for the determination of each metal separately confirming that all electrodes showed differentiated response for the metals. The obtained voltammetric signals provided by the sensor array were processed by Partial Least Squares regression (PLS) to resolve the overlapped nature of the obtained multimetal stripping measurements. This PLS model was built considering a hierarchical model in order to reduce the large amount of data. The method was applied to synthetic mixtures of Cd(II), Pb(II), Tl(I), and Bi(III) in the presence of Zn(II) and In(III) at the levels of μg L−1 and successfully validated with correlation coefficients of both calibration and prediction higher than 0.9 obtained from predicted vs. expected concentration graphs. Moreover, the simultaneous determination of Cd(II), Pb(II), Tl(I), and Bi(III) in the presence of Zn(II) and In(III) in a spiked tap water was also satisfactory achieved, providing comparable results to those obtained by ICP-MS.
Graphical abstract
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Heavy metals translocation and accumulation from the rhizosphere soils to the edible parts of the medicinal plant Fengdan (Paeonia ostii) grown on a metal mining area, China
Publication date: September 2017
Source:Ecotoxicology and Environmental Safety, Volume 143
Author(s): Zhang Jun Shen, De Cong Xu, Yan Song Chen, Zhen Zhang
Fengdan (Paeonia ostii) is one of Chinese 34 famous medicinal materials. This study investigated the concentrations of Arsenic (As), Chromium (Cr), Cadmium (Cd), Copper (Cu), Lead (Pb), Iron (Fe), Manganese (Mn), and Zinc (Zn) in rhizosphere soils, cortex mouton and seeds of Fengdan planted in a metal mining area, China. The mean concentrations of As, Cd, Cu, and Zn in the rhizosphere soils were above the limits set by the Chinese Soil Environmental Quality Standard (GB 15618-1995). The contamination factor (CF) of Cd was >5, while it was >2for As, Cu, Pb, and Zn in all the soils. The integrated pollution index for all the soils was >3 and ˂ 5. Metal concentrations in the edible parts of Fengdan were in the following decreasing order: Mn>Fe>Zn>Cu>Pb>As>Cr≥Cd. The transfer factor mean values for As, Cu, Cd and Fe in the cortex moutan of old Fengdan (over 6 years) were significantly higher than in young Fengdan. Available metal concentrations, pH and soil organic matter content influenced the metal concentrations of the cortex moutan. The results indicated that mining and smelting operations have led to heavy metals contamination of soils and medicinal parts of Fengdan. The major metal pollutants were elemental Cd, Cu, Pb, and Zn. Heavy metals mainly accumulated in the cortex moutan of Fengdan. The mean concentrations of Cd, Cu, and Pb in the old cortex moutan (over 6 years) were above those of the Chinese Green Trade Standards for Medicinal Plants and Preparations in Foreign Trade (WM/T2-2004).
Graphical abstract
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Fate of inorganic elements during fast pyrolysis of biomass in a cyclone reactor
Publication date: 1 September 2017
Source:Fuel, Volume 203
Author(s): Henrik Wiinikka, Ann-Christine Johansson, Linda Sandström, Olov G.W. Öhrman
In order to reduce ash related operational problem and particle emissions during pyrolysis oil combustion it is important to produce pyrolysis oil with very low concentration of inorganics. In this paper, the distribution of all major inorganic elements (S, Si, Al, Ca, Fe, K, Mg, Mn, Na, P, Ti and Zn) in the pyrolysis products (solid residue and two fractions of pyrolysis oil) was investigated during pyrolysis of stem wood, bark, forest residue, salix and reed canary grass. The raw materials were pyrolysed in a cyclone reactor and the produced pyrolysis oils were recovered as two oil fractions, a condensed fraction and an aerosol fraction. The inorganic composition of the ingoing raw material, the solid residue and the two pyrolysis oil fractions were analysed with inductively coupled plasma spectrometry techniques.All major inorganic elements, except sulphur, were concentrated in the solid residue. A significant amount of sulphur was released to the gas phase during pyrolysis. For zinc, potassium and iron about 1–10wt% of the ingoing amount, depending on the raw material, was found in the pyrolysis oil. For the rest of the inorganics, generally less than 1wt% of the ingoing amount was found in the pyrolysis oil. There were also differences in distribution of inorganics between the condensed and the aerosol oil fractions. The easily volatilized inorganic elements such as sulphur and potassium were found to a larger extent in the aerosol fraction, whereas the refractory elements were found to a larger extent in the condensed fraction. This implies that oil fractionation can be a method to produce oil fractions with different inorganic concentrations which thereafter can be used in different technical applications depending on their demand on the inorganic composition of the pyrolysis oil.
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Sources of Dietary Sodium: Implications for Patients, Physicians, and Policy.
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Cardiovascular Outcome Trials in Patients With Advanced Kidney Disease: Time for Action.
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Public Reporting II: State of the Art-Current Public Reporting in Cardiovascular Medicine.
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Sources of Sodium in US Adults From 3 Geographic Regions.
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Effect of Aggressive Blood Pressure Control on the Recurrence of Atrial Fibrillation After Catheter Ablation: A Randomized, Open-Label Clinical Trial (SMAC-AF [Substrate Modification With Aggressive Blood Pressure Control]).
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Impact of Structural Cerebral Damage in Adults With Tetralogy of Fallot.
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Pooled Safety Analysis of Evolocumab in Over 6000 Patients From Double-Blind and Open-Label Extension Studies.
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Percutaneous Therapy for Tricuspid Regurgitation: A New Frontier for Interventional Cardiology.
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Letter by Damen et al Regarding Article, "A Critical Appraisal of Aspirin in Secondary Prevention: Is Less More?".
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Blood Pressure Control in Atrial Fibrillation: One of Many Critical Components in Risk Factor Modification.
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Transcatheter Treatment of Severe Tricuspid Regurgitation With the Edge-to-Edge MitraClip Technique.
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Defined Engineered Human Myocardium With Advanced Maturation for Applications in Heart Failure Modeling and Repair.
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One Stride Forward: Maturation and Scalable Production of Engineered Human Myocardium.
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Screening for Atrial Fibrillation: A Report of the AF-SCREEN International Collaboration.
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Added Sugars and Cardiovascular Disease Risk in Children: A Scientific Statement From the American Heart Association.
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Highlights of the American College of Cardiology Annual Scientific Sessions 2017.
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Wide QRS Complex Tachycardia: What Is the Diagnosis?.
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Response by Valgimigli and Gargiulo to Letter Regarding Article, "A Critical Appraisal of Aspirin in Secondary Prevention: Is Less More?".
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Letter by Puri et al Regarding Article, "Reductions in Atherogenic Lipids and Major Cardiovascular Events: A Pooled Analysis of 10 ODYSSEY Trials Comparing Alirocumab With Control".
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Correction to: Percutaneous Therapy for Tricuspid Regurgitation: A New Frontier for Interventional Cardiology.
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β Cell Renewal versus Differentiation: Slow and Steady Wins the Race
Publication date: 8 May 2017
Source:Developmental Cell, Volume 41, Issue 3
Author(s): Ondine Cleaver
Pancreatic endocrine progenitor cells proliferate and transiently express the bHLH transcription factor Ngn3. In recent issues of Developmental Cell, Azzarelli et al. (2017) and Krentz et al. (2017) demonstrate how CDK phosphorylation of Ngn3 governs the switch between their renewal and differentiation. Lengthening the cell cycle allows Ngn3 accumulation, outpacing phosphorylation-induced degradation.
Teaser
Pancreatic endocrine progenitor cells proliferate and transiently express the bHLH transcription factor Ngn3. In recent issues of Developmental Cell, Azzarelli et al. (2017) and Krentz et al. (2017) demonstrate how CDK phosphorylation of Ngn3 governs the switch between their renewal and differentiation. Lengthening the cell cycle allows Ngn3 accumulation, outpacing phosphorylation-induced degradation.http://ift.tt/2q12BMU
More Cytoplasm, More Problems
Publication date: 8 May 2017
Source:Developmental Cell, Volume 41, Issue 3
Author(s): Predrag Jevtić, Daniel L. Levy
In this issue of Developmental Cell, Kyogoku and Kitajima (2017) investigate the effect of cytoplasmic volume on the fidelity of chromosome segregation during meiosis in mouse oocytes. The authors find that large cytoplasmic volume affects spindle pole morphology, chromosome alignment, and stringency of checkpoint signaling, resulting in error-prone chromosome segregation.
Teaser
In this issue of Developmental Cell, Kyogoku and Kitajima (2017) investigate the effect of cytoplasmic volume on the fidelity of chromosome segregation during meiosis in mouse oocytes. The authors find that large cytoplasmic volume affects spindle pole morphology, chromosome alignment, and stringency of checkpoint signaling, resulting in error-prone chromosome segregation.http://ift.tt/2pYl3rk
RhoD Inhibits RhoC-ROCK-Dependent Cell Contraction via PAK6
Publication date: 8 May 2017
Source:Developmental Cell, Volume 41, Issue 3
Author(s): Charlotte H. Durkin, Flavia Leite, João V. Cordeiro, Yutaka Handa, Yoshiki Arakawa, Ferran Valderrama, Michael Way
RhoA-mediated regulation of myosin-II activity in the actin cortex controls the ability of cells to contract and bleb during a variety of cellular processes, including cell migration and division. Cell contraction and blebbing also frequently occur as part of the cytopathic effect seen during many different viral infections. We now demonstrate that the vaccinia virus protein F11, which localizes to the plasma membrane, is required for ROCK-mediated cell contraction from 2 hr post infection. Curiously, F11-induced cell contraction is dependent on RhoC and not RhoA signaling to ROCK. Moreover, RhoC-driven cell contraction depends on the upstream inhibition of RhoD signaling by F11. This inhibition prevents RhoD from regulating its downstream effector Pak6, alleviating the suppression of RhoC by the kinase. Our observations with vaccinia have now demonstrated that RhoD recruits Pak6 to the plasma membrane to antagonize RhoC signaling during cell contraction and blebbing.
Graphical abstract
Teaser
Many different viral infections induce cell contraction and blebbing. Durkin, Leite, et al. show that during vaccinia infection, RhoC and not RhoA regulates this ROCK-mediated cytopathic effect of cell contraction. They delineate a pathway for RhoC regulation, in which the viral protein F11 blocks RhoC antagonism by RhoD-recruited Pak6.http://ift.tt/2pYyQOS
The Canonical Notch Signaling Pathway: Structural and Biochemical Insights into Shape, Sugar, and Force
Publication date: 8 May 2017
Source:Developmental Cell, Volume 41, Issue 3
Author(s): Rhett A. Kovall, Brian Gebelein, David Sprinzak, Raphael Kopan
The Notch signaling pathway relies on a proteolytic cascade to release its transcriptionally active intracellular domain, on force to unfold a protective domain and permit proteolysis, on extracellular domain glycosylation to tune the forces exerted by endocytosed ligands, and on a motley crew of nuclear proteins, chromatin modifiers, ubiquitin ligases, and a few kinases to regulate activity and half-life. Herein we provide a review of recent molecular insights into how Notch signals are triggered and how cell shape affects these events, and we use the new insights to illuminate a few perplexing observations.
Teaser
In this review, Kovall et al. describe structure-based insights into Notch receptor/ligand interactions, the proteins involved in receptor modifications and cleavage, details on what forces are required to activate Notch, how cell shape might affect this process, and how the active NICD molecule mediates changes in gene expression.http://ift.tt/2q0Igaq
The PomXYZ Proteins Self-Organize on the Bacterial Nucleoid to Stimulate Cell Division
Publication date: 8 May 2017
Source:Developmental Cell, Volume 41, Issue 3
Author(s): Dominik Schumacher, Silke Bergeler, Andrea Harms, Janet Vonck, Sabrina Huneke-Vogt, Erwin Frey, Lotte Søgaard-Andersen
Cell division site positioning is precisely regulated to generate correctly sized and shaped daughters. We uncover the strategy used by the social bacterium Myxococcus xanthus to position the FtsZ cytokinetic ring at midcell. PomX, PomY, and the nucleoid-binding ParA/MinD ATPase PomZ self-assemble forming a large nucleoid-associated complex that localizes at the division site before FtsZ to directly guide and stimulate division. PomXYZ localization is generated through self-organized biased random motion on the nucleoid toward midcell and constrained motion at midcell. Experiments and theory show that PomXYZ motion is produced by diffusive PomZ fluxes on the nucleoid into the complex. Flux differences scale with the intracellular asymmetry of the complex and are converted into a local PomZ concentration gradient across the complex with translocation toward the higher PomZ concentration. At midcell, fluxes equalize resulting in constrained motion. Flux-based mechanisms may represent a general paradigm for positioning of macromolecular structures in bacteria.
Teaser
Schumacher et al. find that the PomXYZ complex self-organizes on the bacterial nucleoid and promotes positioning of the cytokinetic ring. Diffusive fluxes of PomZ into the complex scale with intracellular asymmetry and are converted into a local PomZ concentration gradient that promotes biased motion toward and constrained motion at midcell.http://ift.tt/2q0l5gr
Large Cytoplasm Is Linked to the Error-Prone Nature of Oocytes
Publication date: 8 May 2017
Source:Developmental Cell, Volume 41, Issue 3
Author(s): Hirohisa Kyogoku, Tomoya S. Kitajima
Chromosome segregation during meiosis in oocytes is error prone. The uniquely large cytoplasmic size of oocytes, which provides support for embryogenesis after fertilization, might be a predisposing factor for meiotic errors. However, this hypothesis remains unproven. Here, we show that cytoplasmic size affects the functionality of the acentrosomal spindle. Artificially decreasing the cytoplasmic size in mouse oocytes allows the acentrosomal spindle poles to have a better-focused distribution of microtubule-organizing centers and to biorient chromosomes more efficiently, whereas enlargement of the cytoplasmic size has the opposite effects. Moreover, we found that the cytoplasmic size-dependent dilution of nuclear factors, including anaphase inhibitors that are preformed at the nuclear membrane, limits the spindle's capacity to prevent anaphase entry with misaligned chromosomes. The present study defines a large cytoplasmic volume as a cell-intrinsic feature linked to the error-prone nature of oocytes. This may represent a trade-off between meiotic fidelity and post-fertilization developmental competence.
Graphical abstract
Teaser
Kyogoku and Kitajima show that cytoplasmic size affects the functionality of the acentrosomal spindle and the stringency of the spindle checkpoint in mouse oocytes, thus providing evidence that the large cytoplasmic size of oocytes is linked to error-prone chromosome segregation during female meiosis, which is a leading cause of aneuploidy.http://ift.tt/2q0DXMf
A Geometric Model of Stripe Refinement
Publication date: 8 May 2017
Source:Developmental Cell, Volume 41, Issue 3
Author(s): Eric D. Siggia
Organizing data about patterning and morphogenesis into a coherent framework remains a challenge in developmental biology. Reporting in Science, Corson et al. (2017) apply innovative analysis to an old problem of bristle patterns in Drosophila, reducing the nonlinear interactions among tens of cells to a succinct model with quantitative predictions.
Teaser
Organizing data about patterning and morphogenesis into a coherent framework remains a challenge in developmental biology. Reporting in Science, Corson et al. (2017) apply innovative analysis to an old problem of bristle patterns in Drosophila, reducing the nonlinear interactions among tens of cells to a succinct model with quantitative predictions.http://ift.tt/2pYfoS8
Gastric Acid Secretion from Parietal Cells Is Mediated by a Ca2+ Efflux Channel in the Tubulovesicle
Publication date: 8 May 2017
Source:Developmental Cell, Volume 41, Issue 3
Author(s): Nirakar Sahoo, Mingxue Gu, Xiaoli Zhang, Neel Raval, Junsheng Yang, Michael Bekier, Raul Calvo, Samarjit Patnaik, Wuyang Wang, Greyson King, Mohammad Samie, Qiong Gao, Sasmita Sahoo, Sinju Sundaresan, Theresa M. Keeley, Yanzhuang Wang, Juan Marugan, Marc Ferrer, Linda C. Samuelson, Juanita L. Merchant, Haoxing Xu
Gastric acid secretion by parietal cells requires trafficking and exocytosis of H/K-ATPase-rich tubulovesicles (TVs) toward apical membranes in response to histamine stimulation via cyclic AMP elevation. Here, we found that TRPML1 (ML1), a protein that is mutated in type IV mucolipidosis (ML-IV), is a tubulovesicular channel essential for TV exocytosis and acid secretion. Whereas ML-IV patients are reportedly achlorhydric, transgenic overexpression of ML1 in mouse parietal cells induced constitutive acid secretion. Gastric acid secretion was blocked and stimulated by ML1 inhibitors and agonists, respectively. Organelle-targeted Ca2+ imaging and direct patch-clamping of apical vacuolar membranes revealed that ML1 mediates a PKA-activated conductance on TV membranes that is required for histamine-induced Ca2+ release from TV stores. Hence, we demonstrated that ML1, acting as a Ca2+ channel in TVs, links transmitter-initiated cyclic nucleotide signaling with Ca2+-dependent TV exocytosis in parietal cells, providing a regulatory mechanism that could be targeted to manage acid-related gastric diseases.
Graphical abstract
Teaser
Acid secretion from the parietal cells of the stomach is essential for food digestion. Sahoo et al. identified TRPML1 as a histamine-activated Ca2+ channel in the tubulovesicles required for gastric acid secretion. Synthetic agonists and inhibitors of TRPML1 may be developed to control acid secretion and treat acid-related gastric diseases.http://ift.tt/2pYycRa
Abl Regulates Planar Polarized Junctional Dynamics through β-Catenin Tyrosine Phosphorylation
Publication date: 8 May 2017
Source:Developmental Cell, Volume 41, Issue 3
Author(s): Masako Tamada, Dene L. Farrell, Jennifer A. Zallen
http://ift.tt/2pYpCC5
Surgical treatment of choanal atresia with transnasal endoscopic approach with stentless single side-hinged flap technique: 5 year retrospective analysis
Abstract Introduction: Choanal atresia is a rare congenital malformation of the nasal cavity characterized by the complete obliteration of the posterior choanae. In 67% of cases choanal atresia is unilateral, affecting mainly (71%) the right nasal cavity. In contrast to the unilateral form, bilateral choanal atresia is a life-threatening condition often associated with respiratory distress with feeding and intermittent cyanosis exacerbated by crying. Surgical treatment remains the only therapeutic option. Objective: To report our experience in the use of a transnasal endoscopic approach with stentless single side-hinged flap technique for the surgical management of choanal atresia. Methods: A 5 year retrospective analysis of surgical outcomes of 18 patients treated for choanal atresia with a transnasal technique employing a single side-hinged flap without stent placement. All subjects were assessed preoperatively with a nasal endoscopy and a Maxillofacial computed tomography scan. Results: Ten males and eight females with a mean age at the time of surgery of 20.05 ± 11.32 years, underwent surgery for choanal atresia. Fifteen subjects (83.33%) had a bony while 3 (26.77%) a mixed bony-membranous atretic plate. Two and sixteen cases suffered from bilateral and unilateral choanal atresia respectively. No intra- and/or early postoperative complications were observed. Between 2 and 3 months after surgery two cases (11.11%) of partial restenosis were found. Only one of these presented a relapse of the nasal obstruction and was subsequently successfully repaired with a second endoscopic procedure. Conclusion: The surgical technique described follows the basic requirements of corrective surgery and allows good visualization, evaluation and treatment of the atretic plate and the posterior third of the septum, in order to create the new choanal opening. We believe that the use of a stent is not necessary, as recommended in case of other surgical techniques involving the use of more mucosal flaps.
Resumo Introdução: A atresia de coanas é uma malformação congênita rara da cavidade nasal caracterizada pela obliteração completa da coana posterior. Em 67% dos casos a atresia coanal é unilateral, acomete principalmente (71%) a cavidade nasal direita. Diferentemente da forma unilateral, a atresia coanal bilateral é uma condição com risco de vida, frequentemente associada a insuficiência respiratória à alimentação e cianose intermitente exacerbada pelo choro. O tratamento cirúrgico ainda é a única opção terapêutica. Objetivo: Relatar a nossa experiência no uso de uma abordagem endoscópica transnasal com a técnica de retalho articulado de um lado só sem colocação de stent para o tratamento cirúrgico da atresia coanal. Método: Análise retrospectiva de 5 anos dos desfechos cirúrgicos de 18 pacientes tratados para atresia coanal com uma técnica transnasal com um único retalho de articulação lateral, sem colocação de stent. Todos os indivíduos foram avaliados no pré-operatório com endoscopia nasal e um exame de tomografia computadorizada maxilofacial. Resultados: Dez homens e oito mulheres com idade média de 20,05 ± 11,32 anos à cirurgia foram submetidos a cirurgia para atresia de coanas. Quinze (83,33%) apresentavam placa atrésica óssea e três (26,77%) placa atrésica ósseo-membranosa mista. Dois e 16 casos tinham atresia coanal bilateral e unilateral, respectivamente. Não foram observadas complicações intra e/ou pós-operatórias precoces. Entre 2 e 3 meses após a cirurgia dois casos (11,11%) de restenose parcial foram identificados. Apenas um deles apresentou uma recidiva da obstrução nasal e, portanto, foi reparado com sucesso com um segundo procedimento endoscópico. Conclusão: A técnica cirúrgica descrita segue os requisitos básicos de cirurgia corretiva e possibilita boa visualização, avaliação e tratamento da placa atrésica e do terço posterior do septo, a fim de criar a nova abertura coanal. Pensamos que o uso de um stent não é necessário, tal como recomendado no caso de outras técnicas cirúrgicas que envolvem o uso de mais retalhos de mucosas.
http://ift.tt/2ptHRfu
Temporal processing and long-latency auditory evoked potential in stutterers
Abstract Introduction: Stuttering is a speech fluency disorder, and may be associated with neuroaudiological factors linked to central auditory processing, including changes in auditory processing skills and temporal resolution. Objective: To characterize the temporal processing and long-latency auditory evoked potential in stutterers and to compare them with non-stutterers. Methods: The study included 41 right-handed subjects, aged 18-46 years, divided into two groups: stutterers (n = 20) and non-stutters (n = 21), compared according to age, education, and sex. All subjects were submitted to the duration pattern tests, random gap detection test, and long-latency auditory evoked potential. Results: Individuals who stutter showed poorer performance on Duration Pattern and Random Gap Detection tests when compared with fluent individuals. In the long-latency auditory evoked potential, there was a difference in the latency of N2 and P3 components; stutterers had higher latency values. Conclusion: Stutterers have poor performance in temporal processing and higher latency values for N2 and P3 components.
Resumo Introdução: A gagueira é um distúrbio da fluência da fala e pode estar associada a fatores neuroaudiológicos ligados ao processamento auditivo central, entre eles as alterações das habilidades auditivas de processamento e resolução temporal. Objetivo: Caracterizar o processamento temporal e o potencial evocado auditivo de longa latência em indivíduos gagos e compará-los com indivíduos sem gagueira. Método: Participaram do estudo 41 indivíduos destros, de 18 a 46 anos, distribuídos em dois grupos: 20 com gagueira e 21 sem gagueira, comparados segundo idade, escolaridade e gênero. Todos os indivíduos foram submetidos aos testes de padrão de duração, teste de identificação de intervalos aleatórios e o potencial evocado auditivo de longa latência. Resultados: Indivíduos com gagueira apresentaram pior desempenho nos testes de padrão de duração e Random Gap Detection, quando comparados com os indivíduos fluentes. No potencial evocado auditivo de longa latência, houve diferença na latência dos componentes N2 e P3, os indivíduos gagos apresentaram maiores valores de latência. Conclusão: Os indivíduos com gagueira apresentaram processamento temporal com desempenho abaixo do esperado e um maior valor de latência para os componentes N2 e P3.
http://ift.tt/2ptkTVJ
Surveillance of bacteria Pseudomonas aeruginosa and MRSA associated with chronic suppurative otitis media
Abstract Introduction: Suppurative otitis media is a critical disease causing perforation of the tympanic membrane associated with changes of the mucoperiosteum of the middle ear cleft. Objective: To isolate causative bacteria from chronic suppurative ear discharges and to ascertain their antibiotic profiles, of patients attending outpatients department in 3 years. Methods: For isolation of bacteria, samples of ear discharges were grown in suitable media and bacteria were subjected to antibiotic profiling by the Kirby-Bauer's method with presently used antibiotics. Results: A total of 1043 bacteria were isolated, including Pseudomonas aeruginosa and methicillin resistant Staphylococcus aureus, along with 121 fungal isolates. Among 371 P. aeruginosa isolates, tobramycin 30 had the highest susceptibility rate 93.2%, followed by ceftazidime 30, 91.5% and amikacin 10 µg/disk 64.4%. Of 359 S. aureus isolates, there were 236 coagulase negative S. aureus + methicillin sensitive S. aureus isolates, while 123 isolates were methicillin resistant Staphylococcus aureus with 95.2% isolates susceptible to cloxacillin 15, 83.3% isolates to erythromycin 15 and 78.5% isolates to gentamicin 30 µg/disk. Of 1164, 49 patients presented post aural abscess, 12 patients had intracranial complications, 9 patients had facial palsy and 3 patients had labyrinthitis. More than 90% P. aeruginosa and 90% S. aureus isolates were sensitive to tobramycin 30 and cloxacillin 30 µg/disk, respectively. Conclusion: Multidrug resistant strains of P. aeruginosa were more prevalent than those of S. aureus in ear discharges. Tobramycin and cloxacillin may be included in the formulatory antibiotic regimen to overcome bacterial infections in chronic suppurative otitis media.
Resumo Introdução: Otite média supurativa é uma doença importante que causa perfuração da membrana timpânica, além de alterações do mucoperiósteo da orelha média. Objetivo: Isolar as bactérias causadoras a partir da secreção auricular crônica e verificar seus perfis de sensibilidade aos antibióticos em pacientes ambulatoriais durante três anos. Método: Para o isolamento das bactérias, as amostras de secreções auriculares foram cultivadas em meios adequados e as bactérias foram submetidas à detecção de perfis de sensibilidade aos antibióticos com o método de Kirby-Bauer para antibióticos usados na atualidade. Resultados: No total, 1.043 bactérias, incluindo Pseudomonas aeruginosa resistente à meticilina e Staphylococcus aureus, e 121 fungos isolados foram identificados. Entre 371 isolados de P. aeruginosa, tobramicina 30 µg/disco apresentou a maior taxa de suscetibilidade (93,2%), seguida por ceftazidima 30 µg/disco (91,5%) e amicacina 10 µg/disco (64,4%). De 359 isolados de S. aureus, 236 eram S. aureus coagulase-negativos + S. aureus sensíveis à meticilina (MSSA), enquanto 123 eram MRSA com 95,2% de suscetibilidade à cloxacilina 15 µg/disco, 83,3% sensíveis à eritromicina 15 µg/disco e 78,5% à gentamicina 30 µg/disco. Entre 1.164 pacientes, 49 apresentaram abscesso aural, 12 complicações intracranianas, nove paralisia facial e três labirintite. Mais de 90% das P. aeruginosa isoladas e de 90% de S. aureus eram sensíveis à tobramicina 30 µg/disco e cloxacilina 30 µg/disco, respectivamente. Conclusão: Cepas multirresistentes de P. aeruginosa foram mais prevalentes do que as de S. aureus nas secreções auriculares. Tobramicina e cloxacilina podem ser consideradas na formulação de regime de antibióticos para tratar as infecções bacterianas na OMCS.
http://ift.tt/2pW06ga
Tracheostomy in childhood: review of the literature on complications and mortality over the last three decades
Abstract Introduction: Tracheostomy is a procedure with unique characteristics when used on pediatric patients due to the greater technical difficulty and higher morbidity and mortality rates relative to the procedure in adults. In recent decades, there have been significant changes in the medical care available to children, particularly for those who need intensive care. Surgical conditions have also improved, and there has been an advent of new equipment and medications. These advances have brought changes to both tracheostomy indications and tracheostomy complications. Objective: To perform a review of the articles published over the last three decades on the complications and mortality associated with tracheostomies in children. Methods: Articles were selected from the Cochrane, Latin American and Caribbean Health Sciences Literature, SciELO, National Library of Medicine (Medline Plus), and PubMed online databases. The articles selected had been published between January 1985 and December 2014, and the data was compared using the Chi-square test. Results: A total of 3797 articles were chosen, 47 of which were used as the basis for this review. When the three decades were evaluated as a whole, an increase in tracheostomies in male children under one year of age was found. The most common complications during the period analyzed in descending order of frequency were granuloma, infection, and obstruction of the cannula, accidental decannulation, and post-decannulation tracheocutaneous fistula. In the second and third decades of the review, granulomas represented the most common complication; in the first decade of the review, pneumothoraces were the most common. Mortality associated with tracheostomy ranged from 0% to 5.9%, while overall mortality ranged from 2.2% to 59%. In addition, the review included four studies on premature and/or very underweight infants who had undergone tracheostomies; the studies reported evidence of higher mortality in this age group to be largely associated with underlying diseases. Conclusion: Improved surgical techniques and intensive care, the creation of new medications, and vaccines have all redefined the main complications and the mortality rates of tracheostomy in children. It is a safe procedure that increases chances of survival in those who require the prolonged use of mechanical ventilation.
Resumo Introdução: A traqueostomia é um procedimento com características exclusivas em pacientes pediátricos devido à maior dificuldade técnica e às maiores taxas de morbidade e mortalidade em relação ao procedimento em adultos. Nas últimas décadas, houve mudanças significativas na assistência médica às crianças, especialmente para aquelas que necessitam de cuidados intensivos. As condições cirúrgicas também melhoraram e houve um advento de novos equipamentos e medicamentos. Esses avanços trouxeram mudanças tanto nas indicações de traqueostomia como nas suas complicações. Objetivo: Realizar uma revisão dos artigos publicados nas últimas três décadas sobre as complicações e a mortalidade em crianças submetidas à traqueostomia. Método: Os artigos foram pesquisados nas bases de dados online da Cochrane, Latin American and Caribbean Health Sciences Literature (Lilacs), SciELO, National Library of Medicine (Medline Plus) e PubMed. Os artigos selecionados foram publicados entre janeiro de 1985 e dezembro de 2014 e os dados foram comparados com uso de teste do qui-quadrado. Resultados: Foram selecionados 3.797 artigos, 47 dos quais foram usados como base para esta revisão. Quando as três décadas foram avaliadas como um todo, encontrou-se um aumento das traqueostomias em crianças do sexo masculino com menos de um ano. As complicações mais comuns no período analisado, em ordem decrescente de frequência, foram granuloma, infecção, obstrução da cânula, decanulação acidental e fístula traqueocutânea pós-decanulação. Na segunda e terceira décadas de revisão, os granulomas representaram a complicação mais comum; na primeira década da revisão, pneumotórax foi a mais comum. A mortalidade associada à traqueostomia variou de 0% a 5,9%, enquanto que a mortalidade global variou de 2,2% a 59%. Além disso, a revisão incluiu quatro estudos sobre lactentes prematuros e/ou nascidos com muito baixo peso submetidos à traqueostomia; os estudos mostraram que a mortalidade nessa faixa etária é decorrente associada a doenças subjacentes. Conclusão: A melhoria das técnicas cirúrgicas e de cuidados intensivos e a criação de medicamentos e vacinas redefiniram as principais complicações e as taxas de mortalidade da traqueostomia em crianças.
http://ift.tt/2ptGSMi
Effect of sublingual immunotherapy on platelet activity in children with allergic rhinitis
Abstract Introduction: The role of platelet activation in allergic inflammation is receiving increasing attention. Sublingual immunotherapy for allergic rhinitis can modify the immunological process to an allergen, rather than simply treating symptoms. Objective: The aim of this study was to explore the role of platelet activation during sublingual immunotherapy in children with allergic rhinitis. Methods: Forty-two House Dust Mite - sensitized children with allergic rhinitis were enrolled and received House Dust Mite allergen extract for sublingual immunotherapy or placebo. Serum of different time points during treatment was collected and used for detection of Platelet Factor-4 and Beta-Thromboglobulin concentration by Enzyme-Linked Immuno Sorbent Assay. Results: Our data showed decreased expression of Platelet Factor-4 and Beta-Thromboglobulin protein after one year's sublingual immunotherapy. In addition, the decrease of symptom scores and serum Platelet Factor-4 and Beta-Thromboglobulin protein concentrations was positively related. Conclusion: During sublingual immunotherapy, platelet activation was inhibited significantly. Our results might indicate that inhibition of platelet activation within the systemic circulation is an important mechanism during sublingual immunotherapy.
Resumo Introdução: O papel da ativação de plaquetas na inflamação alérgica recebeu atenção crescente. A imunoterapia sublingual para rinite alérgica pode modificar o processo imunológico a um alérgeno, em vez de tratar os sintomas simplesmente. Objetivo: Explorar o papel da ativação plaquetária durante a imunoterapia sublingual em crianças com rinite alérgica. Método: Quarenta e duas crianças com rinite alérgica sensibilizadas por ácaros de poeira domiciliar (APD) foram inscritas e receberam extrato de alérgeno de APD para imunoterapia sublingual ou placebo. O soro de diferentes pontos no tempo durante o tratamento foi recolhido e usado para a detecção de fator 4 plaquetário e concentração de beta-tromboglobulina por ensaio imunoenzimático. Resultados: Nossos dados mostraram diminuição da expressão de fator 4 plaquetário e proteína beta-tromboglobulina após imunoterapia sublingual de um ano. Além disso, a diminuição dos escores de sintomas e o fator 4 plaquetário sérico e concentrações de proteína beta-tromboglobulina foram relacionados de maneira positiva. Conclusão: Durante imunoterapia sublingual, a ativação plaquetária foi inibida significativamente. Os nossos resultados podem indicar que a inibição da ativação de plaquetas dentro da circulação sistêmica é um mecanismo importante durante imunoterapia sublingual.
http://ift.tt/2pWjk5x
Feasibility of ossicular chain reconstruction with resin cement
Abstract Introduction: Disjunction of ossicular chain is a common finding in middle ear chronic disease. In addition to ossicular interposition, various materials have been used for reconstruction, such as ceramic prostheses, polyethylene, and titanium. Objective: Because of the high cost of the available options, the authors propose to reconstruct the ossicular chain with resin cement, a material typically used in dental reconstruction and fixation. Methods: Two anatomical parts of the temporal bones were used, creating a disjunction of the ossicular chain between the incus and staples and then reconstructing with resin cement. These reconstructions were repeated four times by three different surgeons to ensure the feasibility of the method. Results: A total of 12 reconstructions were carried out, four per surgeon. After applying the cement, it could be verified by touch that the space was filled properly by the used material. Proper articulation with motion transfer to the entire ossicular chain was also observed. Conclusion: Resin cement is a suitable material in the reconstruction of ossicular chain injury, and it is inexpensive and technically simple.
Resumo Introdução: É frequente a disjunção da cadeia ossicular nas doenças crônicas da orelha média. Além de interposições ossiculares, vários materiais já foram usados com a finalidade de reconstruí-la, como próteses de cerâmica, polietileno e titânio. Objetivo: Devido ao alto custo das opções existentes, propomos reconstruir a cadeia com cimento resinoso, material usado normalmente na reconstrução e fixação dentária. Método: Serão usadas duas peças anatômicas de ossos temporais, nas quais será criada uma disjunção da cadeia entre a bigorna e o estribo que, a seguir, será reconstruída com o cimento resinoso. Essas reconstruções serão repetidas quatro vezes por três cirurgiões diferentes, para certificação da viabilidade do método. Resultados: Foram feitas 12 reconstruções, quatro por cada cirurgião. Após aplicação do cimento, conseguimos, ao toque, perceber que o espaço foi preenchido adequadamente pelo material empregado. Notamos ainda adequada articulação com transferência de movimento para toda a cadeia ossicular. Conclusão: O cimento resinoso é um material viável na reconstrução de lesões da cadeia ossicular e proporciona um método tecnicamente simples e de baixo custo.
http://ift.tt/2ptBkBG
Human Papillomavirus and students in Brazil: an assessment of knowledge of a common infection - preliminary report
Abstract Introduction: Human Papillomavirus (HPV) infection is the most prevalent sexually transmitted disease worldwide. One of the barriers to the implementation of prevention programs against the disease is the limited knowledge possessed by most populations regarding the virus and its possible consequences. Objective: The purpose of this study was to evaluate the knowledge of Brazilian college students on transmission, clinical manifestations, and diseases correlated with HPV, highlighting the poor knowledge of a very common infection. Methods: A total of 194 students answered a questionnaire about transmission, clinical features and the possible consequences of persistent HPV infection. The questionnaire was self-applied under the supervision of the authors. Results: The clinical manifestations of HPV infection were not clear to most students. Incorrect assumptions of the clinical manifestations of HPV infection included: bleeding (25%), pain (37%) and rashes (22%). Twelve per cent of respondents did not recognize warts as an HPV-related disease. Regarding potential consequences of persistent infection, students did not recognize a relationship between HPV and laryngeal carcinoma (80.9%), pharyngeal carcinoma (78.9%), anal carcinoma (73.2%), vulvar carcinoma (65.4%) and vaginal carcinoma (54.6%). Large portions of the population evaluated were unaware of modes of HPV transmission beyond genital contact. Conclusion: Knowledge of HPV by the population evaluated in this study is partial and fragmented. Lack of knowledge may contribute to the further spread of the disease. Public health policies for education and guidance of the population should be implemented in Brazil.
Resumo Introdução: A infecção pelo papilomavírus humano (HPV) é a doença sexualmente transmissível mais prevalente em todo o mundo. Uma das barreiras para a implantação de programas de prevenção contra a doença é o conhecimento limitado da maioria das populações sobre o vírus e suas possíveis consequências. Objetivo: Avaliar o conhecimento dos estudantes universitários brasileiros sobre a transmissão, as manifestações clínicas e as doenças correlacionadas com o HPV, com destaque para o pouco conhecimento de uma infecção muito comum. Método: Responderam a um questionário sobre a transmissão, características clínicas e as possíveis consequências da infecção persistente pelo HPV 194 estudantes. O questionário foi autoaplicado, sob a supervisão dos autores. Resultados: As manifestações clínicas da infecção pelo HPV não eram claras para a maioria dos estudantes. As suposições incorretas das manifestações clínicas da infecção pelo HPV incluíam: hemorragia (25%), dor (37%) e erupções cutâneas (22%) -12% dos entrevistados não reconheciam as verrugas como uma doença relacionada ao HPV. Quanto às potenciais consequências da infecção persistente, os alunos não reconheciam uma relação entre HPV e câncer de laringe (80,9%), carcinoma da faringe (78,9%), carcinoma anal (73,2%), carcinoma vulvar (65,4%) e carcinoma vaginal (54,6%). Grandes porções da população avaliada desconheciam os modos de transmissão do HPV além do contato genital. Conclusão: O conhecimento de HPV pela população avaliada neste estudo é parcial e fragmentado. A falta de conhecimento pode contribuir para a propagação da doença. Políticas públicas de saúde para a educação e orientação da população devem ser implantadas no Brasil.
http://ift.tt/2ptHPUU
Evaluation of electrocardiographic parameters in patients with hearing loss genotyped for the connexin 26 gene (GJB2) mutations
Abstract Introduction: Several studies have associated congenital sensorineural hearing loss in children with prolongation of the cardiac parameter QTc. The cause of this association is unknown. At the same time, mutations in GJB2, which encodes connexin 26, are the most common cause of congenital hearing impairment. Objective: To compare electrocardiographic parameters (PR interval, QRS complex, and QTc interval) in patients with hearing loss who were tested for mutations in GJB2 and GJB6 to investigate whether these mutations affect electrical activity of the heart. Methods: 346 patients (176 males, 170 females) with sensorineural hearing loss of 30 dB HL or more, aged 21.8 ± 19.9 years (including 147 children <14 years), underwent both genetic study for GJB2 and GJB6 mutations and electrocardiography. Results: Mutations in GJB2, including homozygotes and heterozygotes, were found in 112 (32%) patients. There were no significant differences in ECG parameters between groups of patients with and without mutations in GJB2. No differences were observed either in men (mean PR with mutation: 155 ± 16.6 vs. 153.6 ± 30.1 without; QRS: 99.9 ± 9.9 vs. 101.1 ± 15.4; QTc: 414.9 ± 29.9 vs. 412.4 ± 25.7) or women (mean PR with: 148.7 ± 21 vs. 143.8 ± 22.8 without; QRS: 94.8 ± 7.6 vs. 92.9 ± 9.6; QTc: 416.8 ± 20.6 vs. 424.9 ± 22.8). In similar fashion, we did we find any significant differences between groups of children with and without GJB2 mutations (mean PR with: 126.3 ± 19.6 vs. 127 ± 19.7 without; QRS: 80.7 ± 9.5 vs. 79.4 ± 11.6; QTc: 419.7 ± 23.5 vs. 419.8 ± 24.8). Conclusion: No association was found between the presence of GJB2 mutations encoding connexin 26 in patients with hearing loss and their ECG parameters (PR, QRS, QTc).
Resumo Introdução: Vários estudos têm associado a perda auditiva neurossensorial congênita em crianças ao prolongamento do parâmetro cardíaco QTc. A causa dessa associação é desconhecida. Ao mesmo tempo, as mutações no GJB2, que codifica a conexina 26, são a causa mais comum de deficiência auditiva congênita. Objetivo: Comparar parâmetros eletrocardiográficos (intervalo PR, complexos QRS e intervalo QTc) em pacientes com perda auditiva que foram testados para mutações no GJB2 e GJB6 para investigar se essas mutações afetam a atividade elétrica do coração. Método: Foram submetidos a estudo genético para mutações de GJB2 e GJB6 e eletrocardiograma 346 pacientes (176 homens, 170 mulheres) com perda auditiva neurossensorial de 30 dB ou mais, com média de 21,8 ± 19,9 anos (incluindo 147 crianças <14 anos). Resultados: Mutações no GJB2, inclusive homozigóticos e heterozigóticos, foram encontradas em 112 (32%) pacientes. Não houve diferenças significativas nos parâmetros de ECG entre grupos de pacientes com e sem mutações no GJB2. Não foram observadas diferenças em homens (PR médio com mutação: 155 ± 16,6 vs. 153,6 ± 30,1 sem mutação; QRS: 99,9 ± 9,9 vs. 101,1 ± 15,4; QTc: 414,9 ± 29,9 vs. 412,4 ± 25,7) nem em mulheres (PR médio com: 148,7 ± 21 vs. 143,8 ± 22,8, sem; QRS: 94,8 ± 7,6 vs. 92,9 ± 9,6; QTc: 416,8 ± 20,6 vs. 424,9 ± 22,8). Da mesma forma, encontramos diferenças significativas entre os grupos de crianças com e sem mutações de GJB2 (PR médio com: 126,3 ± 19,6 vs. 127 ± 19,7, sem; QRS: 80,7 ± 9,5 vs. 79,4 ± 11,6; QTc: 419,7 ± 23,5 vs. 419,8 ± 24,8). Conclusão: Não foi encontrada associação entre a presença de mutações de GJB2 que codificam conexina 26 em pacientes com perda auditiva e seus parâmetros de ECG (PR, QRS, QTc).
http://ift.tt/2pW3VCa
Position statement of the Brazilian Academy of Rhinology on the use of antihistamines, antileukotrienes, and oral corticosteroids in the treatment of inflammatory sinonasal diseases
Abstract Introduction: Inflammatory conditions of the nose and paranasal sinuses are very prevalent in the general population, resulting in marked loss of quality of life in affected patients, as well as significant work, leisure, and social activity losses. These patients require specific and specialized treatment. A wide range of oral medications are available. Objective: The present document is aimed to clarify, for professionals treating patients with inflammatory sinonasal diseases, both specialists and general practitioners, specific oral therapies in noninfectious nasal inflammatory conditions. Methods: The methodology used to create this article included the search for the key words: oral corticosteroids, antihistamines, antileukotrienes, rhinitis, rhinosinusitis in the MEDLINE and EMBASE databases in the last 5 years. Since no relevant article was found for the text on the subject of interest in the last 5 years, the search was extended for another 5 years, and so on, according to the authors' needs. Results: Relevant literature was found regarding the use of antihistamines, antileukotrienes and oral corticosteroids in these conditions. The Brazilian Academy of Rhinology emphasizes, after extensive discussion by the collegiate, key points in the treatment with these drugs. Conclusion: There is support in the literature for the use of these drugs; however, final considerations about the role of each of them have been made.
Resumo Introdução: As afecções inflamatórias do nariz e dos seios paranasais são muito prevalentes na população geral, causam acentuada perda de qualidade de vida dos pacientes afetados, geram perdas significativas das atividades de trabalho, lazer e sociais. Esses pacientes necessitam de tratamento específico e especializado e uma ampla gama de medicações orais está disponível. Objetivo: O presente documento tem por objetivo esclarecer àqueles que tratam das doenças nasossinusais inflamatórias, tanto especialistas quanto generalistas, sobre as terapêuticas orais nas afecções inflamatórias nasais não infecciosas. Método: A metodologia usada para elaboração deste artigo incluiu a busca das palavras chave: corticosteroides orais, anti-histamínicos, antileucotrienos, rinite, rinossinusite nos bancos de dados Medline e Embase nos últimos 5 anos. Como não foi achado artigo relevante para o texto sobre o assunto de interesse nos últimos 5 anos, a busca foi estendida por mais 5 anos, e assim por diante, de acordo com a necessidade dos autores. Resultados: Literatura relevante foi encontrada com relação ao uso dos anti-histamínicos, antileucotrienos e corticosteroides orais nessas afecções. A Academia Brasileira de Rinologia ressalta, após amplo debate do colegiado, pontos-chave no tratamento com esses medicamentos. Conclusão: Há respaldo na literatura para o uso desses medicamentos, entretanto considerações finais acerca do papel de cada deles foram feitas.
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Characteristics of 419 patients with acquired middle ear cholesteatoma
Abstract Introduction: Cholesteatoma is a destructive lesion that can result in life-threatening complications. Typically, it presents with hypoacusis and continuous otorrhea as symptoms. Because it is a rare disease, there are few studies in Brazil describing the characteristics of patients with the disease. Objective: This study aimed to determine the prevalence of cholesteatoma in patients with chronic otitis media and describe clinical, audiological and surgical characteristics of patients with acquired middle ear cholesteatoma treated at a referral hospital in the public health system. Methods: Cross-sectional and prospective cohort study, including 1710 patients with chronic otitis media, treated between August 2000 and June 2015, without prior surgery. Detailed clinical history, videotoscopy, and audiometry were performed, in addition to review of medical records to search for surgical data. Cholesteatomas were classified according to their route of formation. Results: Of the patients with chronic otitis media, 419 (24.5%) had cholesteatoma; mean age of 34.49 years; 53.5% female and 63.8% adults. Bilateral cholesteatoma was observed in 17.1%. Anterior epitympanic cholesteatoma corresponded to 1.9%; posterior epitympanic, 32.9%; posterior mesotympanic, 33.7%; two routes, 14.8%; and indeterminate, 16.7%. The mean air-bone gap was 29.84 dB and did not differ between routes of formation. There were no correlations between gap size and patient age or duration of symptoms. Of the surgical cases, 16.8% underwent closed tympanomastoidectomy and 75.2% open tympanomastoidectomy. Conclusion: The prevalence of cholesteatoma in patients with chronic otitis media was 24.5% and it was more common in adults than in children. Posterior mesotympanic cholesteatoma was more frequent, with no difference in mean air-bone gap between the different routes of formation. In patients undergoing surgery, open tympanomastoidectomy was the procedure most frequently chosen.
Resumo Introdução: Colesteatoma é uma lesão destrutiva que pode levar a complicações potencialmente letais. Tipicamente, apresenta hipoacusia e otorreia contínua como sintomas. Por ser uma doença rara, existem poucos estudos no Brasil que descrevam as características destes pacientes. Objetivo: O presente estudo teve como objetivos determinar a prevalência de colesteatoma entre os pacientes com otite média crônica (OMC) e descrever as características clínicas, audiológicas e cirúrgicas dos pacientes com colesteatoma adquirido de orelha média atendidos em um hospital de referência do sistema público de saúde. Método: Estudo transversal e de coorte prospectivo, incluindo 1.710 pacientes com OMC, atendidos entre agosto de 2000 e junho de 2015, sem tratamento cirúrgico prévio. Foram feitas anamnese detalhada, videotoscopia e audiometria, além de revisão de prontuários para busca de dados cirúrgicos. Os colesteatomas foram classificados conforme sua via de formação. Resultados: Dos pacientes com otite média crônica, 419 (24,5%) apresentavam colesteatoma. Média de 34,49 anos; 53,5% do sexo feminino e 63,8% adultos. Colesteatoma foi observado bilateralmente em 17,1%. Os epitimpânicos anteriores corresponderam a 1,9%; os epitimpânicos posteriores a 32,9%; os mesotimpânicos posteriores a 33,7%; duas vias a 14,8% e indeterminados a 16,7%. A média tritonal dos gaps aeroósseos foi de 29,84 dB e não diferiu entre os grupos segundo as vias de formação. Não foram observadas correlações entre tamanho do gap e idade do paciente ou duração dos sintomas. Dos pacientes operados, 16,8% foram submetidos a timpanomastoidectomia fechada e 75,2% a timpanomastoidectomia aberta. Conclusão: A prevalência de colesteatoma em pacientes com otite média crônica foi de 24,5% e foi mais frequente em adultos do que em crianças. Os mesotimpânicos posteriores foram mais frequentes, não foi observada diferença na média dos gaps aeroósseos entre diferentes vias de formação. Nos pacientes submetidos a cirurgia, a timpanomastoidectomia aberta foi o procedimento escolhido.
http://ift.tt/2pVTEpC
Effect of conductive hearing loss on central auditory function
Abstract Introduction: It has been demonstrated that long-term Conductive Hearing Loss (CHL) may influence the precise detection of the temporal features of acoustic signals or Auditory Temporal Processing (ATP). It can be argued that ATP may be the underlying component of many central auditory processing capabilities such as speech comprehension or sound localization. Little is known about the consequences of CHL on temporal aspects of central auditory processing. Objective: This study was designed to assess auditory temporal processing ability in individuals with chronic CHL. Methods: During this analytical cross-sectional study, 52 patients with mild to moderate chronic CHL and 52 normal-hearing listeners (control), aged between 18 and 45 year-old, were recruited. In order to evaluate auditory temporal processing, the Gaps-in-Noise (GIN) test was used. The results obtained for each ear were analyzed based on the gap perception threshold and the percentage of correct responses. Results: The average of GIN thresholds was significantly smaller for the control group than for the CHL group for both ears (right: p = 0.004; left: p < 0.001). Individuals with CHL had significantly lower correct responses than individuals with normal hearing for both sides (p < 0.001). No correlation was found between GIN performance and degree of hearing loss in either group (p > 0.05). Conclusion: The results suggest reduced auditory temporal processing ability in adults with CHL compared to normal hearing subjects. Therefore, developing a clinical protocol to evaluate auditory temporal processing in this population is recommended.
Resumo Introdução: Já foi demonstrado que a perda auditiva condutiva (PAC), em longo prazo, pode influenciar na detecção precisa das características temporais dos sinais acústicos ou do processamento auditivo temporal (PAT). Pode-se argumentar que o PAT pode ser o componente subjacente de muitos recursos do processamento auditivo central, como a compreensão da fala ou localização do som. Pouco se sabe sobre as consequências da PAC nos aspectos temporais do processamento auditivo central. Objetivo: Este estudo foi projetado para avaliar a capacidade de processamento auditivo temporal em indivíduos com PAC crônica. Método: Durante este estudo transversal analítico, 52 pacientes com PAC crônica leve a moderada e 52 indivíduos com audição normal (controle), entre 18 e 45 anos, foram recrutados. Para avaliar o processamento auditivo temporal, foi usado o teste de resolução temporal Gaps-in-Noise (GIN). Os resultados obtidos para cada orelha foram analisados com base no limiar de percepção da quebra de continuidade (gap) e na porcentagem de respostas corretas. Resultados: A média dos limiares no GIN foi significativamente menor para o grupo controle do que para o grupo PAC em ambas as orelhas (direita: p = 0,004; esquerda: p < 0,001). Os indivíduos com PAC apresentaram respostas corretas significativamente mais baixas do que os indivíduos com audição normal em ambas as orelhas (p < 0,001). Não houve correlação entre o desempenho no GIN e o grau de perda auditiva em ambos os grupos (p > 0,05). Conclusão: Os resultados sugerem uma redução da capacidade de processamento auditivo temporal em adultos com PAC comparados com indivíduos que apresentam audição normal. Portanto, o desenvolvimento de um protocolo clínico para avaliar o processamento auditivo temporal nessa população é recomendado.
http://ift.tt/2pW0lrQ
Characteristics of 419 patients with acquired middle ear cholesteatoma
Abstract Introduction: Cholesteatoma is a destructive lesion that can result in life-threatening complications. Typically, it presents with hypoacusis and continuous otorrhea as symptoms. Because it is a rare disease, there are few studies in Brazil describing the characteristics of patients with the disease. Objective: This study aimed to determine the prevalence of cholesteatoma in patients with chronic otitis media and describe clinical, audiological and surgical characteristics of patients with acquired middle ear cholesteatoma treated at a referral hospital in the public health system. Methods: Cross-sectional and prospective cohort study, including 1710 patients with chronic otitis media, treated between August 2000 and June 2015, without prior surgery. Detailed clinical history, videotoscopy, and audiometry were performed, in addition to review of medical records to search for surgical data. Cholesteatomas were classified according to their route of formation. Results: Of the patients with chronic otitis media, 419 (24.5%) had cholesteatoma; mean age of 34.49 years; 53.5% female and 63.8% adults. Bilateral cholesteatoma was observed in 17.1%. Anterior epitympanic cholesteatoma corresponded to 1.9%; posterior epitympanic, 32.9%; posterior mesotympanic, 33.7%; two routes, 14.8%; and indeterminate, 16.7%. The mean air-bone gap was 29.84 dB and did not differ between routes of formation. There were no correlations between gap size and patient age or duration of symptoms. Of the surgical cases, 16.8% underwent closed tympanomastoidectomy and 75.2% open tympanomastoidectomy. Conclusion: The prevalence of cholesteatoma in patients with chronic otitis media was 24.5% and it was more common in adults than in children. Posterior mesotympanic cholesteatoma was more frequent, with no difference in mean air-bone gap between the different routes of formation. In patients undergoing surgery, open tympanomastoidectomy was the procedure most frequently chosen.
Resumo Introdução: Colesteatoma é uma lesão destrutiva que pode levar a complicações potencialmente letais. Tipicamente, apresenta hipoacusia e otorreia contínua como sintomas. Por ser uma doença rara, existem poucos estudos no Brasil que descrevam as características destes pacientes. Objetivo: O presente estudo teve como objetivos determinar a prevalência de colesteatoma entre os pacientes com otite média crônica (OMC) e descrever as características clínicas, audiológicas e cirúrgicas dos pacientes com colesteatoma adquirido de orelha média atendidos em um hospital de referência do sistema público de saúde. Método: Estudo transversal e de coorte prospectivo, incluindo 1.710 pacientes com OMC, atendidos entre agosto de 2000 e junho de 2015, sem tratamento cirúrgico prévio. Foram feitas anamnese detalhada, videotoscopia e audiometria, além de revisão de prontuários para busca de dados cirúrgicos. Os colesteatomas foram classificados conforme sua via de formação. Resultados: Dos pacientes com otite média crônica, 419 (24,5%) apresentavam colesteatoma. Média de 34,49 anos; 53,5% do sexo feminino e 63,8% adultos. Colesteatoma foi observado bilateralmente em 17,1%. Os epitimpânicos anteriores corresponderam a 1,9%; os epitimpânicos posteriores a 32,9%; os mesotimpânicos posteriores a 33,7%; duas vias a 14,8% e indeterminados a 16,7%. A média tritonal dos gaps aeroósseos foi de 29,84 dB e não diferiu entre os grupos segundo as vias de formação. Não foram observadas correlações entre tamanho do gap e idade do paciente ou duração dos sintomas. Dos pacientes operados, 16,8% foram submetidos a timpanomastoidectomia fechada e 75,2% a timpanomastoidectomia aberta. Conclusão: A prevalência de colesteatoma em pacientes com otite média crônica foi de 24,5% e foi mais frequente em adultos do que em crianças. Os mesotimpânicos posteriores foram mais frequentes, não foi observada diferença na média dos gaps aeroósseos entre diferentes vias de formação. Nos pacientes submetidos a cirurgia, a timpanomastoidectomia aberta foi o procedimento escolhido.
http://ift.tt/2pVTEpC
Effect of conductive hearing loss on central auditory function
Abstract Introduction: It has been demonstrated that long-term Conductive Hearing Loss (CHL) may influence the precise detection of the temporal features of acoustic signals or Auditory Temporal Processing (ATP). It can be argued that ATP may be the underlying component of many central auditory processing capabilities such as speech comprehension or sound localization. Little is known about the consequences of CHL on temporal aspects of central auditory processing. Objective: This study was designed to assess auditory temporal processing ability in individuals with chronic CHL. Methods: During this analytical cross-sectional study, 52 patients with mild to moderate chronic CHL and 52 normal-hearing listeners (control), aged between 18 and 45 year-old, were recruited. In order to evaluate auditory temporal processing, the Gaps-in-Noise (GIN) test was used. The results obtained for each ear were analyzed based on the gap perception threshold and the percentage of correct responses. Results: The average of GIN thresholds was significantly smaller for the control group than for the CHL group for both ears (right: p = 0.004; left: p < 0.001). Individuals with CHL had significantly lower correct responses than individuals with normal hearing for both sides (p < 0.001). No correlation was found between GIN performance and degree of hearing loss in either group (p > 0.05). Conclusion: The results suggest reduced auditory temporal processing ability in adults with CHL compared to normal hearing subjects. Therefore, developing a clinical protocol to evaluate auditory temporal processing in this population is recommended.
Resumo Introdução: Já foi demonstrado que a perda auditiva condutiva (PAC), em longo prazo, pode influenciar na detecção precisa das características temporais dos sinais acústicos ou do processamento auditivo temporal (PAT). Pode-se argumentar que o PAT pode ser o componente subjacente de muitos recursos do processamento auditivo central, como a compreensão da fala ou localização do som. Pouco se sabe sobre as consequências da PAC nos aspectos temporais do processamento auditivo central. Objetivo: Este estudo foi projetado para avaliar a capacidade de processamento auditivo temporal em indivíduos com PAC crônica. Método: Durante este estudo transversal analítico, 52 pacientes com PAC crônica leve a moderada e 52 indivíduos com audição normal (controle), entre 18 e 45 anos, foram recrutados. Para avaliar o processamento auditivo temporal, foi usado o teste de resolução temporal Gaps-in-Noise (GIN). Os resultados obtidos para cada orelha foram analisados com base no limiar de percepção da quebra de continuidade (gap) e na porcentagem de respostas corretas. Resultados: A média dos limiares no GIN foi significativamente menor para o grupo controle do que para o grupo PAC em ambas as orelhas (direita: p = 0,004; esquerda: p < 0,001). Os indivíduos com PAC apresentaram respostas corretas significativamente mais baixas do que os indivíduos com audição normal em ambas as orelhas (p < 0,001). Não houve correlação entre o desempenho no GIN e o grau de perda auditiva em ambos os grupos (p > 0,05). Conclusão: Os resultados sugerem uma redução da capacidade de processamento auditivo temporal em adultos com PAC comparados com indivíduos que apresentam audição normal. Portanto, o desenvolvimento de um protocolo clínico para avaliar o processamento auditivo temporal nessa população é recomendado.
http://ift.tt/2pW0lrQ
Assessment of hearing threshold in adults with hearing loss using an automated system of cortical auditory evoked potential detection
Abstract Introduction: The use of hearing aids by individuals with hearing loss brings a better quality of life. Access to and benefit from these devices may be compromised in patients who present difficulties or limitations in traditional behavioral audiological evaluation, such as newborns and small children, individuals with auditory neuropathy spectrum, autism, and intellectual deficits, and in adults and the elderly with dementia. These populations (or individuals) are unable to undergo a behavioral assessment, and generate a growing demand for objective methods to assess hearing. Cortical auditory evoked potentials have been used for decades to estimate hearing thresholds. Current technological advances have lead to the development of equipment that allows their clinical use, with features that enable greater accuracy, sensitivity, and specificity, and the possibility of automated detection, analysis, and recording of cortical responses. Objective: To determine and correlate behavioral auditory thresholds with cortical auditory thresholds obtained from an automated response analysis technique. Methods: The study included 52 adults, divided into two groups: 21 adults with moderate to severe hearing loss (study group); and 31 adults with normal hearing (control group). An automated system of detection, analysis, and recording of cortical responses (HEARLab®) was used to record the behavioral and cortical thresholds. The subjects remained awake in an acoustically treated environment. Altogether, 150 tone bursts at 500, 1000, 2000, and 4000 Hz were presented through insert earphones in descending-ascending intensity. The lowest level at which the subject detected the sound stimulus was defined as the behavioral (hearing) threshold (BT). The lowest level at which a cortical response was observed was defined as the cortical electrophysiological threshold. These two responses were correlated using linear regression. Results: The cortical electrophysiological threshold was, on average, 7.8 dB higher than the behavioral for the group with hearing loss and, on average, 14.5 dB higher for the group without hearing loss for all studied frequencies. Conclusion: The cortical electrophysiological thresholds obtained with the use of an automated response detection system were highly correlated with behavioral thresholds in the group of individuals with hearing loss.
Resumo Introdução: O uso da amplificação sonora por pessoas com perda auditiva oferece uma melhor qualidade de vida. O acesso a esse recurso e o seu benefício podem ficar comprometidos no caso de pacientes que apresentem dificuldades ou limitações na avaliação audiológica tradicional comportamental, tais como neonatos e crianças pequenas, presença do espectro da neuropatia auditiva e do autismo, déficit intelectual e presença de estados demenciais de adultos e idosos. Essas populações (ou indivíduos) incapazes de participar de uma avaliação comportamental geram uma crescente demanda por métodos objetivos de avaliação auditiva. Os potenciais evocados auditivos corticais são usados há décadas, com a finalidade de estimar os limiares auditivos. Avanços tecnológicos atuais permitiram o desenvolvimento de equipamentos que possibilitam seu uso clínico, dotados de recursos que permitem maior precisão, sensibilidade e especificidade, além da possibilidade de detecção, análise e registro automatizados das respostas corticais. Objetivo: Determinar e correlacionar o limiar auditivo comportamental com o limiar auditivo cortical obtido em equipamento de análise automatizada das respostas. Método: Participaram do estudo 52 adultos, distribuídos em dois grupos: 21 com perda de grau moderado a severo (grupo estudo) e 31 com audição normal (grupo controle). Para o registro dos limiares comportamentais e corticais foi usado um equipamento dotado de um sistema com detecção, análise e registro automatizados das respostas corticais (HEARLab®). Os participantes permaneceram despertos, em um ambiente acusticamente tratado. Foram apresentados 150 estímulos tipo tone burst nas frequências de 500, 1.000, 2.000 e 4.000 Hz, por meio de fones de inserção em intensidades descendente-ascendente. O menor nível no qual o sujeito detectou a presença do estímulo sonoro foi definido como o limiar auditivo comportamental. O menor nível no qual uma resposta cortical estava presente foi definido como o limiar eletrofisiológico cortical. Essas duas respostas foram correlacionadas por meio da regressão linear. Resultados: O limiar eletrofisiológico cortical foi, em média, 7,8 dB superior ao comportamental para o grupo com perda auditiva e 14,5 dB superior, em média, para o grupo sem perda auditiva para todas as frequências estudadas. Conclusão: Os limiares eletrofisiológicos corticais obtidos por meio de um sistema de detecção automatizado de respostas estavam fortemente correlacionados com os limiares comportamentais no grupo de indivíduos com perda auditiva.
http://ift.tt/2pW7IiP