Cytotoxicity, genotoxicity and antimutagenicity of hexane extracts of Agaricus blazei determined in vitro by the comet assay and CHO/HGPRT gene mutation assay

Agaricus blazei Murrill ss. Heinem, known as the sun mushroom or himematsutake, is a basidiomycete native to Brazil, which is popular for its medicinal properties. The aim of this study was to test hexane extracts (one fraction and its four sub-fractions) of A. blazei for bioactivity in cultured mammalian cells (CHO-K1). The comet assay, the colony forming assay (CFA) and CHO/HGPRT gene mutation assay were used respectively to determine genotoxicity, cytotoxicity and antimutagenicity of these extracts at different concentrations. The cells were incubated in culture medium and treated for 3 h according to the standard protocol for each assay. The DNA damage-inducing agent ethylmethane sulfonate (EMS) was utilized as the positive control and also in combination with extracts to test for a protective effect. Statistical analysis of the data was performed using analysis of variance (ANOVA) and Tukey's test. A relationship between cytotoxicity and genotoxicity could be established and two extracts EH6B and EH6D showed a protective tendency, while the others did not, with the primary extract EH6 causing the most substantial damage to genetic material. These findings warrant more in-depth studies of the active principles of this mushroom. (c) 2005 Elsevier Ltd. All rights reserved.

Observational study on efficacy of negative expiratory pressure test proposed as screening for obstructive sleep apnea syndrome among commercial interstate bus drivers - protocol study

Background: Obstructive sleep apnea (OSA) is a respiratory disease characterized by the collapse of the extrathoracic airway and has important social implications related to accidents and cardiovascular risk. The main objective of the present study was to investigate whether the drop in expiratory flow and the volume expired in 0.2 s during the application of negative expiratory pressure (NEP) are associated with the presence and severity of OSA in a population of professional interstate bus drivers who travel medium and long distances.Methods/Design: An observational, analytic study will be carried out involving adult male subjects of an interstate bus company. Those who agree to participate will undergo a detailed patient history, physical examination involving determination of blood pressure, anthropometric data, circumference measurements (hips, waist and neck), tonsils and Mallampati index. Moreover, specific questionnaires addressing sleep apnea and excessive daytime sleepiness will be administered. Data acquisition will be completely anonymous. Following the medical examination, the participants will perform a spirometry, NEP test and standard overnight polysomnography. The NEP test is performed through the administration of negative pressure at the mouth during expiration. This is a practical test performed while awake and requires little cooperation from the subject. In the absence of expiratory flow limitation, the increase in the pressure gradient between the alveoli and open upper airway caused by NEP results in an increase in expiratory flow.Discussion: Despite the abundance of scientific evidence, OSA is still underdiagnosed in the general population. In addition, diagnostic procedures are expensive, and predictive criteria are still unsatisfactory. Because increased upper airway collapsibility is one of the main determinants of OSA, the response to the application of NEP could be a predictor of this disorder. With the enrollment of this study protocol, the expectation is to encounter predictive NEP values for different degrees of OSA in order to contribute toward an early diagnosis of this condition and reduce its impact and complications among commercial interstate bus drivers.

Towards Interoperability in P2P World: an Indexing Middleware for Multi-Protocol Peer-to-Peer Data Sharing

Despite the abundant availability,of protocols and application for peer-to-peer file sharing, several drawbacks are still present in the field. Among most notable drawbacks is the lack of a simple and interoperable way to share information among independent peer-to-peer networks. Another drawback is the requirement that the shared content can be accessed only by a limited number of compatible applications, making impossible their access to others applications and system. In this work we present a new approach for peer-to-peer data indexing, focused on organization and retrieval of metadata which describes the shared content. This approach results in a common and interoperable infrastructure, which provides a transparent access to data shared on multiple data sharing networks via a simple API. The proposed approach is evaluated using a case study, implemented as a cross-platform extension to Mozilla Fir fox browser; and demonstrates the advantages of such interoperability over conventional distributed data access strategies.

Prevention of experimental venous thrombosis induced by contrast medium in the rat

In order to assess experimentally the usefulness of some procedures employed in man to prevent venous thrombosis following phlebography, thrombosis was induced in rats using sodium diatrizoate in a temporarily isolated segment of a jugular vein. The prevention of thrombosis was attempted by washing out the vein with physiologic saline or saline plus heparin or by injecting saline plus heparin in the opposite jugular vein. Thrombosis occurred in all animals in the control group and in the group treated with saline alone. Both treatment schemes with heparin significantly reduced the incidence of thrombosis, the wash out with heparin being more effective than systemic heparin.

Control of amylase production and growth characteristics of Aspergillus ochraceus

The growth and the extracellular amylase production by Aspergillus ochraceus were studied in a stationary culture medium. Maximum growth rate of this fungus was found after 5 days of incubation at 30° C, but maximum amylase production was obtained after 2 days. The highest amylase production were attained with lactose, maltose, xylose and starch as carbon sources. The extracellular amylase production and mycelial growth were influenced by the concentration of starch. Other carbohydrates supported growth but did not induce amylase synthesis and glucose repressed it, indicating catabolite repression in this microorganism. The presence of both mechanisms of induction and repression suggests that at least these multiple forms of regulation are present in A. ochraceus. Of the nitrogen sources tested, casaminoacids, ammonium nitrate and sodium nitrate stimulated the highest yield of amylase. Optimal amylase production was obtained at pH 5.0, but enzyme activity was found only in the 4.0-6.0 pH range. These results were probably due to the inhibitory effect of NH 4 +-N in the culture medium.

Protocol to refine intestinal motility test in mice

We propose a new protocol intended to conform to the 3Rs (replacement, reduction, and refinement) principle, using animals fasted for 3 h to control intestinal motility, which reduced stress in the animals. In this new protocol, mice are deprived of food for a short time (3 h) and are not killed. The mice are observed until evacuation containing charcoal is observed, and the experimental results are based on the charcoal evacuation time. The present study may aid the formulation of recommendations that can be included in revised guidelines relating to the fasting time of mice. This new concept of an intestinal motility test conforms with respectful science.

Efeito da sacarose e sorbitol na conservação in vitro de Passiflora giberti N. E. Brown

This work objectified the study of sucrose and sorbitol effect in the in vitro conservation for Passiflora giberti N. E. Brown, access. Therefore, an experiment was conducted in a completely randomized design to compare control treatment (standard MS) to MS medium supplemented with three sucrose concentrations (0, 15 and 30 g L -1) combined with three sorbitol concentrations (10, 20 and 40 g L -1), in a total of 10 treatments with 20 replicas. The experiment evaluation was carried out at 30, 60, 90 and 120 days of incubation, whereas the height of shoots (cm), number of roots, number and color of leaves were observed. The results showed the possibility to maintain passion-fruit microplants for a four months period under slow growth in MS medium supplemented with 10 or 20 g L -1 of sorbitol, without sucrose, and kept under 16 hours photoperiod (22 μ E m -2 s -1) and temperature of 27 ± 1°C. Sucrose sustained the longest development of the microplants. Root formation was affected by the sorbitol in the concentration of 40 g L -1 and by the absence of sucrose in the culture medium.

Modernizing the Brazilian active control network

The Brazilian Network for Continuous Monitoring of GPS - RBMC, since its foundation in December of 1996, has been playing an essential role for the maintenance and user access of the fundamental geodetic frame in the country,. It provides users with a direct link to the Brazilian Geodetic System - SGB. Its role has become more relevant with the increasing use of space navigation technology in the country. Recently, Brazil adopted a new geodetic system, SIRGAS2000, in February 2005, fully compatible with GNSS technology. The paper provides an overview of the recent modernization phases the RBMC network has undergone highlighting its future steps. From its current post-mission mode, the RBMC will evolve into a real-time network, providing real-time data and real-time correction to users. The network enhanced with modern GPS receivers and the addition of atomic clocks will be used to compute WADGPS-type corrections to be transmitted, in real time, to users in Brazil and surrounding areas. It is estimated that users will be able to achieve a horizontal accuracy around 0.5 m (1σ) in static and kinematic positioning and better for dual frequency users. The availability of the WADGPS service will allow users to tie to the new SIRGAS2000 system in a more rapid and transparent way for positioning and navigation applications. It should be emphasized that support to post-mission static positioning will continue to be provided to users interested in higher accuracy levels. In addition to this, a post-mission Precise Point Positioning (PPP) service will be provided based on the one currently provided by the Geodetic Survey Division of NRCan (CSRS-PPP). The modernization of the RBMC is under development based on a cooperation signed at the end of 2004 with the University of New Brunswick, supported by the Canadian International Development Agency and the Brazilian Cooperation Agency. The Geodetic Survey Division of NRCan is also participating in this modernization effort under the same project.

Glycogen storage and muscle glucose transporters (GLUT-4) of mice selectively bred for high voluntary wheel running

To examine the evolution of endurance-exercise behaviour, we have selectively bred four replicate lines of laboratory mice (Mus domesticus) for high voluntary wheel running ('high runner' or HR lines), while also maintaining four non-selected control (C) lines. By generation 16, HR mice ran ∼2.7-fold more than C mice, mainly by running faster (especially in females), a differential maintained through subsequent generations, suggesting an evolutionary limit of unknown origin. We hypothesized that HR mice would have higher glycogen levels before nightly running, show greater depletion of those depots during their more intense wheel running, and have increased glycogen synthase activity and GLUT-4 protein in skeletal muscle. We sampled females from generation 35 at three times (photophase 07:00 h-19:00 h) during days 5-6 of wheel access, as in the routine selection protocol: Group 1, day 5, 16:00 h-17:30 h, wheels blocked from 13:00 h; Group 2, day 6, 02:00 h-03:30 h (immediately after peak running); and Group 3, day 6, 07:00 h-08:30 h. An additional Group 4, sampled 16:00 h-17:30 h, never had wheels. HR individuals with the mini-muscle phenotype (50% reduced hindlimb muscle mass) were distinguished for statistical analyses comparing C, HR normal, and HR mini. HR mini ran more than HR normal, and at higher speeds, which might explain why they have been favored by the selective-breeding protocol. Plasma glucose was higher in Group 1 than in Group 4, indicating a training effect (phenotypic plasticity). Without wheels, no differences in gastrocnemius GLUT-4 were observed. After 5 days with wheels, all mice showed elevated GLUT-4, but HR normal and mini were 2.5-fold higher than C. At all times and irrespective of wheel access, HR mini showed approximately three-fold higher [glycogen] in gastrocnemius and altered glycogen synthase activity. HR mini also showed elevated glycogen in soleus when sampled during peak running. All mice showed some glycogen depletion during nightly wheel running, in muscles and/or liver, but the magnitude of this depletion was not large and hence does not seem to be limiting to the evolution of even-higher wheel running.

Towards interoperability in P2Pworld: An indexing middleware for multi-protocol peer-to-peer data sharing

Despite the abundant availability of protocols and application for peer-to-peer file sharing, several drawbacks are still present in the field. Among most notable drawbacks is the lack of a simple and interoperable way to share information among independent peer-to-peer networks. Another drawback is the requirement that the shared content can be accessed only by a limited number of compatible applications, making impossible their access to others applications and system. In this work we present a new approach for peer-to-peer data indexing, focused on organization and retrieval of metadata which describes the shared content. This approach results in a common and interoperable infrastructure, which provides a transparent access to data shared on multiple data sharing networks via a simple API. The proposed approach is evaluated using a case study, implemented as a cross-platform extension to Mozilla Firefox browser, and demonstrates the advantages of such interoperability over conventional distributed data access strategies. © 2009 IEEE.

Latest Enhancements in the Brazilian Active Control Network

The Brazilian Network for Continuous Monitoring of GPS - RBMC, since its foundation in December of 1996, has been playing an essential role for the maintenance and user access of the fundamental geodetic frame in the country. It provides to users a direct link to the Brazilian Geodetic System. Its role has become more relevant with the increasing use of space navigation technology in the country. Recently, Brazil adopted a new geodetic frame, SIRGAS2000, in February 2005, fully compatible with GNSS technology. The paper provides an overview of the recent modernization phases the RBMC network has undergone highlighting its future steps. From its current post-mission mode, the RBMC will evolve into a real-time network, providing real-time data and real-time correction to users. The network enhanced with modern GPS receivers and the addition of atomic clocks will be used to compute WADGPS-type corrections to be transmitted, in real time, to users in Brazil and surrounding areas. It is estimated that users will be able to achieve a horizontal accuracy around 0.5 m (1 σ) in static and kinematic positioning and better for dual frequency users. The availability of the WADGPS service will allow users to tie to the new SIRGAS2000 frame in a more rapid and transparent way for positioning and navigation applications. It should be emphasized that support to post-mission static positioning, will continue to be provided to users interested in higher accuracy levels. In addition to this, a post-mission Precise Point Positioning (PPP) service will be provided based on the one currently provided by the Geodetic Survey Division of NRCan (CSRS-PPP). The modernization of the RBMC is under development based on a cooperation signed at the end of 2004 with the University of New Brunswick, supported by the Canadian International Development Agency and the Brazilian Cooperation Agency. The Geodetic Survey Division of NRCan is also participating in this modernization effort under the same project. © Springer-Verlag Berlin Heidelberg 2009.

Shaping the future of social protection: access, financing and solidarity

Includes bibliography

SMEs in the environmental goods and services market: identifying areas of opportunity, policies and instruments: case studies: Argentina, Chile, Colombia and Mexico

Includes bibliography

Public-private partnerships in renewable energy in Latin America and the Caribbean

Incluye Bibliografía

E-commerce and export promotion policies for small- and medium-sized enterprises: East Asian and Latin American experiences

Includes bibliography