Search

The axon initial segment is a specialized compartment of the proximal axon of CNS neurons where action potentials are initiated. However, it remains unknown whether this domain is assembled in sensory dorsal root ganglion neurons, in which spikes are initiated in the peripheral terminals. Here we investigate whether sensory neurons have an axon initial segment and if it contributes to spontaneous activity in neuropathic pain. Our results demonstrate that myelinated dorsal root ganglion neurons assemble an axon initial segment in the proximal region of their stem axon, enriched in the voltage-gated sodium channels Nav1.1 and Nav1.7. Using correlative immunofluorescence and calcium imaging, we demonstrate that the Nav1.7 channels at the axon initial segment are associated with spontaneous activity. Computer simulations further indicate that the axon initial segment plays a key role in the initiation of spontaneous discharges by lowering their voltage threshold. Finally, using a Cre-based mouse model for time-controlled axon initial segment disassembly, we demonstrate that this compartment is a major source of spontaneous discharges causing mechanical allodynia in neuropathic pain. Thus, an axon initial segment domain is present in sensory neurons and facilitates their spontaneous activity. This study provides a new insight in the cellular mechanisms that cause pathological pain and identifies a new potential target for chronic pain management. [ABSTRACT FROM AUTHOR]

Background: Poincaré delay maps are widely used in the analysis of cardiac interbeat interval (RR) dynamics. To facilitate visualization of the structure of these time series, we introduce multiscale Poincaré (MSP) plots.Methods: Starting with the original RR time series, the method employs a coarse-graining procedure to create a family of time series, each of which represents the system's dynamics in a different time scale. Next, the Poincaré plots are constructed for the original and the coarse-grained time series. Finally, as an optional adjunct, color can be added to each point to represent its normalized frequency.Results: We illustrate the MSP method on simulated Gaussian white and 1/f noise time series. The MSP plots of 1/f noise time series reveal relative conservation of the phase space area over multiple time scales, while those of white noise show a marked reduction in area. We also show how MSP plots can be used to illustrate the loss of complexity when heartbeat time series from healthy subjects are compared with those from patients with chronic (congestive) heart failure syndrome or with atrial fibrillation.Conclusions: This generalized multiscale approach to Poincaré plots may be useful in visualizing other types of time series. [ABSTRACT FROM AUTHOR]

The aim of this paper was to assess the validity and reliability of the touch-screen standard Portuguese version of the following patient-reported outcomes (PROs), compared with paper format, in patients with rheumatoid arthritis (RA) and spondyloarthritis: Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), Bath Ankylosing Spondylitis Functional Index (BASFI), Ankylosing Spondylitis Quality of Life scale (ASQoL), Short-Form 36 (SF-36), Health Assessment Questionnaire (HAQ) and visual analogue scales (VAS) measuring pain and burden of disease. Adult patients with RA and spondyloarthritis attending the Portuguese Institute of Rheumatology were recruited from March 2013 to January 2014. Patients filled the paper and touch-screen formats of the standard Portuguese versions of the PROs. Two groups of VAS were used, RA and psoriatic arthritis (Global VAS) and another specific for spondyloarthrites (Spa-VAS). Paper questionnaires were filled 15 min before touch-screen formats. Agreement between formats (validity) was assessed by intraclass correlation coefficient (ICC), while internal consistency of scales (reliability) was assessed by Cronbach's alpha. Overall, 134 patients were included with a mean age of 51 years, 74.6 % female and 57.5 % presenting RA. BASDAI, BASFI, HAQ and ASQoL showed high ICC between paper and touch-screen formats (0.977, 0.958, 0.974 and 0.940, respectively). ICC for Global VAS ranged from 0.906 to 0.921, while Spa-VAS ranged from 0.867 to 0.943. The mean ICC for all SF-36 domains was 0.889 (ICC for each domain ranged from 0.781 to 0.944). Touch-screen standard Portuguese formats of these PROs may be valid and reliable tools for PRO measurement in rheumatology. [ABSTRACT FROM AUTHOR]

The growth of mobile phone users has lead to a dramatic increasing of SMS spam messages. Recent reports clearly indicate that the volume of mobile phone spam is dramatically increasing year by year. In practice, fighting such plague is difficult by several factors, including the lower rate of SMS that has allowed many users and service providers to ignore the issue, and the limited availability of mobile phone spam-filtering software. Probably, one of the major concerns in academic settings is the scarcity of public SMS spam datasets, that are sorely needed for validation and comparison of different classifiers. Moreover, traditional content-based filters may have their performance seriously degraded since SMS messages are fairly short and their text is generally rife with idioms and abbreviations. In this paper, we present details about a new real, public and non-encoded SMS spam collection that is the largest one as far as we know. Moreover, we offer a comprehensive analysis of such dataset in order to ensure that there are no duplicated messages coming from previously existing datasets, since it may ease the task of learning SMS spam classifiers and could compromise the evaluation of methods. Additionally, we compare the performance achieved by several established machine learning techniques. In summary, the results indicate that the procedure followed to build the collection does not lead to near-duplicates and, regarding the classifiers, the Support Vector Machines outperforms other evaluated techniques and, hence, it can be used as a good baseline for further comparison. [ABSTRACT FROM AUTHOR]

Abstract: Mg2+-dependent ATPases were investigated in Malpighian tubules of the blood-sucking insect, Triatoma infestans, with cytochemical procedures for light and electron microscopy. The aim was to establish patterns of enzyme occurrence in the blood-sucking insect under control rearing conditions for further comparisons with animals subjected to the action of stress factors. Enzyme activity was found in laminated “concretions” present in distal cells, in edges of urate crystals at the lumen of the proximal region of tubules, in the basement membrane of proximal cells, and variously distributed in plasmalemma invaginations of both distal and proximal cells. Presence of ATPases in the “concretions” and urate crystals is presumed to be due to engulfment of other ATPase-containing components during formation of these structures. Cytochemical reactivity in the basement membrane and plasmalemma invaginations is assumed to be involved with active transport of waste molecules from and to hemolymph and differs as a function of the Malpighian tubule region. This paper provides a basic understanding of the enzyme occurrence in the blood sucking insects, and can be used as a pattern for comparative means of the staining patterns among Triatominae species. [Copyright &y& Elsevier]

After trauma, regeneration of adult CNS axons is abortive, causing devastating neurologic deficits. Despite progress in rehabilitative care, there is no effective treatment that stimulates axonal growth following injury. Using models with different regenerative capacities, followed by gain- and loss-of-function analysis, we identified profilin 1 (Pfn1) as a coordinator of actin and microtubules (MTs), powering axonal growth and regeneration. In growth cones, Pfn1 increased actin retrograde flow, MT growth speed, and invasion of filopodia by MTs, orchestrating cytoskeletal dynamics toward axonal growth. In vitro, active Pfn1 promoted MT growth in a formin-dependent manner, whereas localization of MTs to growth cone filopodia was facilitated by direct MT binding and interaction with formins. In vivo, Pfn1 ablation limited regeneration of growth-competent axons after sciatic nerve and spinal cord injury. Adeno-associated viral (AAV) delivery of constitutively active Pfn1 to rodents promoted axonal regeneration, neuromuscular junction maturation, and functional recovery of injured sciatic nerves, and increased the ability of regenerating axons to penetrate the inhibitory spinal cord glial scar. Thus, we identify Pfn1 as an important regulator of axonal regeneration and suggest that AAV-mediated delivery of constitutively active Pfn1, together with the identification of modulators of Pfn1 activity, should be considered to treat the injured nervous system. [ABSTRACT FROM AUTHOR]

An experiment to establish the best reaction conditions for the transesterification of soybean oil is described. We conducted the ethylic and methylic routes using two different protocols, and evaluated how the variables time, stirring, alcohol/oil molar ratio, catalyst (%), catalyst type, and temperature affected the process. The highest yield of biodiesel was obtained using the following conditions: ethylic route – t = 60 min, stirring: 100 rpm, ethanol/oil molar ratio = 12:1, catalyst relative to oil (%) = 0.2%, catalyst = potassium ethoxide, temperature = 35 °C; methylic route – t = 30 min, stirring: 100 rpm, methanol/oil molar ratio = 6:1, catalyst (%) = 0.2%, catalyst = KOH, temperature = 55 °C. We analyzed the acidity, moisture content, density at 20 °C, kinematic viscosity at 40 °C, oxidative stability, and carbon residue at the biodiesels obtained under optimal conditions. The results were consistent with the values allowed by the Brazilian ANP (Resolution 07/2008). We also conducted the physicochemical analysis of the soybean oil used as feedstock to produce biodiesel. [ABSTRACT FROM AUTHOR]

Various effective methods have been developed to measure the concentration of viruses in sediment samples. However, there is need to standardize less laborious and simpler techniques. The objective of the present study was to compare two different methods to measure the concentration of viruses in soil samples. The use of polyethylene glycol (PEG) was compared with a direct extraction of viral nucleic acids from the samples diluted in modified Eagle's minimal essential medium (E-MEM). The presence of adenovirus in the samples was detected by real-time quantitative polymerase chain reaction (qPCR). Only six samples (30%) were positive for adenovirus when PEG technique was used. The direct method showed 16 (80%) samples positive for adenovirus. Therefore, direct detection (i.e. without previous concentration) demonstrated a higher rate of detection, better effectiveness, and shorter execution time. Furthermore, direct detection uses reagents that are often readily available in virology laboratories. Thus, it is an attractive alternative to other methods of detection of virus particles in sediments. [ABSTRACT FROM AUTHOR]