Surface miscibility of EPC/DOTAP/DOPE in binary and ternary mixed monolayers

Surface pressure (pi)-molecular area (A) curves were used to characterize the packing of pseudo-ternary mixed Langmuir monolayers of egg phosphatidylcholine (EPC), 1,2-dioleoyl-3-trimethylammonium propane (DOTAP) and L-alpha-dioleoyl phosphatidylethanolamine (DOPE). This pseudo-ternary mixture EPC/DOPE/DOTAP has been successfully employed in liposome formulations designed for DNA non-viral vectors. Pseudo-binary mixtures were also studied as a control. Miscibility behavior was inferred from pi-A curves applying the additivity rule by calculating the excess free energy of mixture (Delta G(Exc)). The interaction between the lipids was also deduced from the surface compressional modulus (C(s)(-1)). The deviation from ideality shows dependence on the lipid polar head type and monolayer composition. For lower DOPE concentrations, the forces are predominantly attractive. However, if the monolayer is DOPE rich, the DOTAP presence disturbs the PE-PE intermolecular interaction and the net interaction is then repulsive. The ternary monolayer EPC/DOPE/DOTAP presented itself in two configurations, modulated by the DOPE content, in a similar behavior to the DOPE/DOTAP monolayers. These results contribute to the understanding of the lipid interactions and packing in self-assembled systems associated with the in vitro and in vivo stability of liposomes. (C) 2010 Elsevier B.V. All rights reserved.

Patterns of brain asymmetry in the perception of positive and negative facial expressions

The divided visual field technique was used to investigate the pattern of brain asymmetry in the perception of positive/approach and negative/withdrawal facial expressions. A total of 80 undergraduate students (65 female, 15 male) were distributed in five experimental groups in order to investigate separately the perception of expressions of happiness, surprise, fear, sadness, and the neutral face. In each trial a target and a distractor expression were presented simultaneously in a computer screen for 150 ms and participants had to determine the side (left or right) on which the target expression was presented. Results indicated that expressions of happiness and fear were identified faster when presented in the left visual field, suggesting an advantage of the right hemisphere in the perception of these expressions. Fewer judgement errors and faster reaction times were also observed for the matching condition in which emotional faces were presented in the left visual field and neutral faces in the right visual field. Other results indicated that positive expressions (happiness and surprise) were perceived faster and more accurately than negative ones (sadness and fear). Main results tend to support the right hemisphere hypothesis, which predicts a better performance of the right hemisphere to perceive emotions, as opposed to the approach-withdrawal hypothesis.

Two novel reports of semidry stigmatic surface in Asteraceae

Research documents related to the morphology and function of style branches and stigmatic surface of Asteraceae are still rather few, and the literature reports are thus controversial. We report in the present study that the stigmatic surfaces of two non-related species of Asteraceae (Lessingianthus grandiflorus and Lucilia lycopodioides) have features of semidry stigmas. Sporodermis of both species was also analyzed so that we could understand how the stigmatic surface works during pollen deposition and rehydration. Stylar branches and pollen grains (sporodermis) were studied using scanning and transmission electron microscopy (SEM and TEM) and histochemistry techniques. The inner and marginal bands of stylar branches in these species display intermediary features between the dry and wet types of stigma: the cuticle characterizes the dry stigma and cells with secretory activity characterize the wet stigma; these showed differences from what has been described to the Asteraceae family, where stigmatic surface of species from several tribes is considered dry. Pollen grains are medium-size to large with exine ornamentation (echinate and echinolophate) and abundant secretion which latter characterizes pollenkitt. We can assume that two processes might help pollen grain hydration on stigmatic surface in Lessingianthus grandiflorus and Lucilia lycopodioides: (1) the presence of pollenkitt, as observed in the secretory content inside exine cavities and around pollen grains; and (2) the secretory activity of stigmatic surface cells, whose secretion accumulates among intercellular and subcuticular spaces and leads to cuticle disruption during the floral receptive phase. Our results suggest that ultrastructural and histochemical studies should be considered when describing stigmatic surface and that the ""semidry"" feature within Asteraceae should be investigated still more in detail, so that the taxonomic or adaptation value of this trait in the family can be verified. (C) 2010 Elsevier GmbH. All rights reserved.

The Effect of Expectancy of a Threatening Event on Time Perception in Human Adults

Two experiments were conducted to investigate the effect of a threatening stimulus in human adults in a temporal bisection task. In Experiment I. for two anchor duration conditions (400/800 vs. 800/1600 ms), the participants completed trials in which the probe duration was followed by an aversive stimulus or a nonaversive stimulus. The results showed that the duration was judged longer when the participants expected an aversive rather than a nonaversive stimulus. In Experiment 2, the effect of the temporal localization of the aversive stimulus was also tested, with the aversive stimulus being presented at the beginning or at the end of the probe duration. The results revealed a temporal overestimation in each condition compared to the trials in which no aversive stimulus was presented. Furthermore, the temporal overestimation was greater when the expectation for the forthcoming threatening stimulus was longer. This temporal overestimation is explained in terms of a speeding-up of the neural timing system in response to the increase in the arousal level produced by the expectation of a threatening stimulus.

Results of high dose-rate brachytherapy boost before 2D or 3D external beam irradiation for prostate cancer

Background and purpose: To evaluate biochemical control and treatment related toxicity of patients with localized adenocarcinoma of the prostate treated with high dose-rate brachytherapy (HDRB) combined with conventional 2D or 3D-conformal external beam irradiation (EBI). Material and methods: Four-hundred and three patients treated between December 2000 and March 2004. HDRB was delivered with three fractions of 5.5-7 Gy with a single implant, followed by 45 Gy delivered with 2D or 3D conformal EBI. Results: The median follow-up was 48.4 months. Biochemical failure (BF) occurred in 9.6% according to both ASTRO and Phoenix consensus criteria. Mean time to relapse was 13 and 26 months, respectively. The 5-year BF free survival using the ASTRO criteria was 94.3%, 86.9% and 86.6% for the low, intermediate and high risk groups, respectively; using Phoenix criteria, 92.4%, 88.0% and 85.3%, respectively. The only predictive factor of BF in the multivariate analysis by both ASTRO and Phoenix criteria was the presence of prostate nodules detected by digital palpation, and patients younger than 60 years presented a higher chance of failure using Phoenix criteria only. Conclusions: Treatment scheme is feasible and safe with good efficacy. (C) 2011 Elsevier Ireland Ltd All rights reserved. Radiotherapy and Oncology 98 (2011) 169-174

INTENSITY-MODULATED AND 3D-CONFORMAL RADIOTHERAPY FOR WHOLE-VENTRICULAR IRRADIATION AS COMPARED WITH CONVENTIONAL WHOLE-BRAIN IRRADIATION IN THE MANAGEMENT OF LOCALIZED CENTRAL NERVOUS SYSTEM GERM CELL TUMORS

Purpose: To compare the sparing potential of cerebral hemispheres with intensity-modulated radiotherapy (IMRT) and three-dimensional conformal radiotherapy (3D-CRT) for whole-ventricular irradiation (WVI) and conventional whole-brain irradiation (WBI) in the management of localized central nervous system germ cell tumors (CNSGCTs). Methods and Materials: Ten cases of patients with localized CNSGCTs and submitted to WVI by use of IMRT with or without a ""boost"" to the primary lesion were selected. For comparison purposes, similar treatment plans were produced by use of 3D-CRT (WVI with or without boost) and WBI (opposed lateral fields with or without boost), and cerebral hemisphere sparing was evaluated at dose levels ranging from 2 Gy to 40 Gy. Results: The median prescription dose for WVI was 30.6 Gy (range, 25.2-37.5 Gy), and that for the boost was 16.5 Gy (range, 0-23.4 Gy). Mean irradiated cerebral hemisphere volumes were lower for WVI with IMRT than for 3D-CRT and were lower for WVI with 3D-CRT than for WBI. Intensity-modulated radiotherapy was associated with the lowest irradiated volumes, with reductions of 7.5%, 12.2%, and 9.0% at dose levels., compared with 3D-CRT. Intensity-modulated radiotherapy provided of 20, 30, and 40 Gy, respectively statistically significant reductions of median irradiated volumes at all dose levels (p = 0.002 or less). However, estimated radiation doses to peripheral areas of the body were 1.9 times higher with IMRT than with 3D-CRT. Conclusions: Although IMRT is associated with increased radiation doses to peripheral areas of the body, its use can spare a significant amount of normal central nervous system tissue compared with 3D-CRT or WBI in the setting of CNSGCT treatment. (C) 2010 Elsevier Inc.

Use of SVM Methods with Surface-Based Cortical and Volumetric Subcortical Measurements to Detect Alzheimer`s Disease

Here, we examine morphological changes in cortical thickness of patients with Alzheimer`s disease (AD) using image analysis algorithms for brain structure segmentation and study automatic classification of AD patients using cortical and volumetric data. Cortical thickness of AD patients (n = 14) was measured using MRI cortical surface-based analysis and compared with healthy subjects (n = 20). Data was analyzed using an automated algorithm for tissue segmentation and classification. A Support Vector Machine (SVM) was applied over the volumetric measurements of subcortical and cortical structures to separate AD patients from controls. The group analysis showed cortical thickness reduction in the superior temporal lobe, parahippocampal gyrus, and enthorhinal cortex in both hemispheres. We also found cortical thinning in the isthmus of cingulate gyrus and middle temporal gyrus at the right hemisphere, as well as a reduction of the cortical mantle in areas previously shown to be associated with AD. We also confirmed that automatic classification algorithms (SVM) could be helpful to distinguish AD patients from healthy controls. Moreover, the same areas implicated in the pathogenesis of AD were the main parameters driving the classification algorithm. While the patient sample used in this study was relatively small, we expect that using a database of regional volumes derived from MRI scans of a large number of subjects will increase the SVM power of AD patient identification.

Leptospirosis pulmonary haemorrhage syndrome is associated with linear deposition of immunoglobulin and complement on the alveolar surface

Leptospirosis is a zoonotic infection associated with severe diseases such as leptospirosis pulmonary haemorrhage syndrome (LPHS). The cause of pulmonary haemorrhage is unclear. Understanding which mechanisms and processes are involved in LPHS will be important in treatment regimens under development for this life-threatening syndrome. In the present study, we evaluated 30 lung specimens from LPHS patients and seven controls using histology and immunohistochemistry (detection of IgM, IgG, IgA and C3) in order to describe the pathological features associated with this syndrome. Immunoglobulin deposits were detected on the alveolar surface in 18/30 LPHS patients. Three staining patterns were observed for the immunoglobulins and C3 in the lung tissues of LPHS patients: AS, delicate linear staining adjacent to the alveolar surface, which was indicative of a membrane covering the luminal surface of type I and II pneumocyte cells; S, heterogeneous staining which was sporadically distributed along the alveolar septum; and IA, weak, focal intra-alveolar granular staining. Human LPHS is associated with individual and unique histological patterns that differ from those of other causes of pulmonary haemorrhage. In the present study, it was found that the linear deposition of immunoglobulins (IgA, IgG and IgM) and complement on the alveolar surface may play a role in the pathogenesis of pulmonary haemorrhage in human leptospirosis.

Influence of silence and attention on tinnitus perception

OBJECTIVE: The purpose of this study was to study the effect of attention and sustained silence on the emergence of auditory phantom perception in normal-hearing adults. STUDY DESIGN: Cross-sectional survey. SUBJECTS AND METHODS: While sitting in a sound booth, 66 volunteers (age range. 18-65; mean age, 37.3) performed 3 experiments of 5 minutes each, consecutively and randomly presented. Two deviated attention from auditory system (Hanoi and visual attention experiments). and 1 drove attention to the auditory system (auditory attention). After each experiment, participants were asked about their auditory and visual perception. No sound or light change was given at any moment. RESULTS: Of the participants, 19.7% experienced tinnitus during Hanoi, 45.5% during visual attention, and 68.2% during auditory attention experiment. with no significant differences for studied variables. CONCLUSION: Tinnitus-like perceptions may occur in a non-clinical population in a silent environment. Concomitant auditory attention plays an important role on the emergence of tinnitus. (C) 2008 American Academy of Otolaryngology-Head and Neck Surgery Foundation. All rights reserved.

Speech perception in adolescents with pre-lingual hearing impairment with cochlear implants

Profound hearing loss is a disability that affects personality and when it involves teenagers before language acquisition, these bio-psychosocial conflicts can be exacerbated, requiring careful evaluation and choice of them for cochlear implant. Aim: To evaluate speech perception by adolescents with profound hearing loss, users of cochlear Implants. Study Design: Prospective. Materials and Methods: Twenty-five individuals with severe or profound pre-lingual hearing loss who underwent cochlear implantation during adolescence, between 10 to 17 years and 11 months, who went through speech perception tests before the implant and 2 years after device activation. For comparison and analysis we used the results from tests of four choice, recognition of vowels and recognition of sentences in a closed setting and the open environment. Results: The average percentage of correct answers in the four choice test before the implant was 46.9% and after 24 months of device use, this value went up to 86.1% in the vowels recognition test, the average difference was 45.13% to 83.13% and the sentences recognition test together in closed and open settings was 19.3% to 60.6% and 1.08% to 20.47% respectively. Conclusion: All patients, although with mixed results, achieved statistical improvement in all speech tests that were employed.

The effects of chronic exposure to traffic derived air pollution on the ocular surface

Objectives: The purpose of this study was to explore the clinical relevance of chronic exposure to ambient levels of traffic derived air pollution on the ocular surface. Methods: A panel study involving 55 volunteers was carried out in Sao Paulo, Brazil. We measured the mean individual levels of nitrogen dioxide (NO(2)) exposure for 7 days. All subjects answered the Ocular Symptom Disease Index (OSDI) and a symptoms inventory. Subsequently, subjects underwent Schirmer I test, biomicroscopy, vital staining and tear breakup time (TOUT) assessment. Subject`s mean daily exposure to NO(2) was categorized in quartiles. Statistical analysis was performed using one-way ANOVA, Tukey HSD and Chi-Square tests. Results: A dose-response pattern was detected between OSDI scores and NO(2) quartiles (p < 0.05). There was a significant association between NO(2) quartiles and reported ocular irritation (X(2) = 9.2, p < 0.05) and a significant negative association between TBUT and NO(2) exposure (p < 0.05, R = -0.316. Spearman`s correlation). There was a significant increase in the frequency of meibomitis in subjects exposed to higher levels of NO(2) (p < 0.05). Conclusions: Subjects exposed to higher levels of traffic derived air pollution reported more ocular discomfort symptoms and presented greater tear film instability, suggesting that the ocular discomfort symptoms and tear breakup time could be used as convenient bioindicators of the adverse health effects of traffic derived air pollution exposure. (C) 2010 Elsevier Inc. All rights reserved.

Bovine Bone Screws: Metrology and Effects of Chemical Processing and Ethylene Oxide Sterilization on Bone Surface and Mechanical Properties

We assess the effects of chemical processing, ethylene oxide sterilization, and threading on bone surface and mechanical properties of bovine undecalcified bone screws. In addition, we evaluate the possibility of manufacturing bone screws with predefined dimensions. Scanning electronic microscopic images show that chemical processing and ethylene oxide treatment causes collagen fiber amalgamation on the bone surface. Processed screws hold higher ultimate loads under bending and torsion than the in natura bone group, with no change in pull-out strength between groups. Threading significantly reduces deformation and bone strength under torsion. Metrological data demonstrate the possibility of manufacturing bone screws with standardized dimensions.

Brown spider venom toxins interact with cell surface and are endocytosed by rabbit endothelial cells

Bites from the Loxosceles genus (brown spiders) cause severe clinical symptoms, Including dermonecrotic injury, hemorrhage, hemolysis, platelet aggregation and renal failure. Histological findings of dermonecrotic lesions in animals exposed to Loxosceles intermedia venom show numerous vascular alterations Study of the hemorrhagic consequences of the venom in endothelial cells has demonstrated that the degeneration of blood vessels results not only from degradation of the extracellular matrix molecule or massive leukocyte infiltration, but also from a direct and primary activity of the venom on endothelial cells. Exposure of an endothelial cell line in vitro to L. intermedia venom induce morphological alterations, such as cell retraction and disadhesion to the extracellular matrix. The aim of the present study was to investigate the interaction between the venom toxins and the endothelial cell surface and their possible internalization, in order to illuminate the information about the deleterious effect triggered by venom After treating endothelial cells with venom toxins, we observed that the venom Interacts with cell surface. Venom treatment also can cause a reduction of cell surface glycoconjugates When cells were permeabilized, it was possible to verify that some venom toxins were internalized by the endothelial cells The venom internalization involves endocytic vesicles and the venom was detected in the lysosomes. However, no damage to lysosomal integrity was observed, suggesting that the cytotoxic effect evoked by L interned:a venom on endothelial cells is not mediated by venom internalization (C) 2010 Elsevier Ltd. All rights reserved

Perception of dysphagia: lack of correlation with objective measurements of esophageal function

Background The mechanism underlying increased perception of food bolus passage in the absence of esophageal mechanical obstruction has not been completely elucidated. A correlation between the intensity of the symptom and the severity of esophageal dysfunction, either motility (manometry) or bolus transit (impedance) has not been clearly demonstrated. The aim of this study was to analyze the correlation between objective esophageal function assessment (with manometry and impedance) and perception of bolus passage in healthy volunteers (HV) with normal and pharmacologically-induced esophageal hypocontractility, and in patients with gastro-esophageal reflux disease (GERD) with and without ineffective esophageal motility (IEM). Methods Combined manometry-impedance was performed in 10 HV, 19 GERD patients without IEM and nine patients with IEM. Additionally, nine HV were studied after 50 mg sildenafil, which induced esophageal peristaltic failure. Perception of each 5 mL viscous swallow was evaluated using a 5-point scale. Manometry identified hypocontractility (contractions lower than 30 mmHg) and impedance identified incomplete bolus clearance. Key Results In HV and in GERD patients with and without IEM, there was no association between either manometry or impedance and perception on per swallow analysis (OR: 0.842 and OR: 2.017, respectively), as well as on per subject analysis (P = 0.44 and P = 0.16, respectively). Lack of correlation was also found in HV with esophageal hypocontractility induced by sildenafil. Conclusions & Inferences There is no agreement between objective measurements of esophageal function and subjective perception of bolus passage. These results suggest that increased bolus passage perception in patients without mechanical obstruction might be due to esophageal hypersensitivity.

Ageing and surface EMG activity patterns of masticatory muscles

P>The purpose of this study was to evaluate the influence of age on the electromyographic activity of masticatory muscles. All volunteers were Brazilian, fully dentate (except for Group I - mixed dentition), Caucasian, aged 7-80, and divided into five groups: I (7-12 years), II (13-20 years), III (21-40 years), IV (41-60 years) and V (61-80 years). Except for Group V, which comprised nine women and eight men, all groups were equally divided with respect to gender (20 M/20 F). Surface electromyographic records of masticatory muscles were obtained at rest and during maximal voluntary contraction, right and left laterality, maximal jaw protrusion and maximal clenching in the intercuspal position. Statistically significant differences (P < 0 center dot 05) were found in all clinical conditions among the different age groups. Considerably different patterns of muscle activation were found across ages, with greater electromyographic activity in children and youth, and decreasing from adults to aged people.