Use of Medical Subject Headings (MeSH) in Portuguese for categorizing web-based healthcare content

Introduction: Internet users are increasingly using the worldwide web to search for information relating to their health. This situation makes it necessary to create specialized tools capable of supporting users in their searches. Objective: To apply and compare strategies that were developed to investigate the use of the Portuguese version of Medical Subject Headings (MeSH) for constructing an automated classifier for Brazilian Portuguese-language web-based content within or outside of the field of healthcare, focusing on the lay public. Methods: 3658 Brazilian web pages were used to train the classifier and 606 Brazilian web pages were used to validate it. The strategies proposed were constructed using content-based vector methods for text classification, such that Naive Bayes was used for the task of classifying vector patterns with characteristics obtained through the proposed strategies. Results: A strategy named InDeCS was developed specifically to adapt MeSH for the problem that was put forward. This approach achieved better accuracy for this pattern classification task (0.94 sensitivity, specificity and area under the ROC curve). Conclusions: Because of the significant results achieved by InDeCS, this tool has been successfully applied to the Brazilian healthcare search portal known as Busca Saude. Furthermore, it could be shown that MeSH presents important results when used for the task of classifying web-based content focusing on the lay public. It was also possible to show from this study that MeSH was able to map out mutable non-deterministic characteristics of the web. (c) 2010 Elsevier Inc. All rights reserved.

Clinical relationships and ethical problems in primary care, Sao Paulo, SP, Brazil

Objectives: Main Objective: to identify ethical problems in primary care according to nurses` and doctors` perceptions. Secondary Objective: to know ethical issues of patient-professional relationships in primary care. Design: Synthesis to integrate and reinterpret primary results of qualitative studies. Setting: Primary healthcare centers, Sao Paulo, SP, Brazil. Participants and/or context: Incidental sample of 34 nurses and 36 medical doctors working in primary healthcare centers selected by convenience. Methods: Individual, semi-structured interviews to identity situations considered as sources of ethical problems. The sample is socially representative of primary care health centers and professionals. Data collection assured discourse saturation. Hermeneutic-dialectical discourse analysis was used to study the results. Results: Patient-professional relationships and team work were the main sources of ethical problems. The most important problems were patient information, privacy, confidentiality, interpersonal relationship, linkage and patient autonomy. These issues reflect the recent changes in clinical relation ships and show the peculiarities of primary care with its continuous care which lasts a long time. Healthcare involves multiprofessional team work in the midst of the patient claims for autonomy. Good care of patients needs requires a relationship based on communication and cooperation, and includes feelings and values, with communication skills. Conclusions: Ethical problems in primary care are common situations. For quality and humane primary care the relationship should consist of dialogue, trust and cooperation. (C) 2009 Elsevier Espana, S.L. All rights reserved.

Obtaining polymeric composite membranes from lignocellulosic components of sugarcane bagasse for use in wastewater treatment

Currently, several research groups and industries are studying applications for the residues from agrobusiness, other than burning them. Thinking about a better use for the sugarcane bagasse, this study aims to obtain membranes of cellulose acetate composite with oxidized lignin, both isolated from sugarcane bagasse. Thus, we obtain a product with higher commercial value, from a natural fiber, which has applications in water and effluent treatment, and further contributes to the maintenance of the environment. Macromolecular components of bagasse were separated by steam explosion pre-treatment and a basic treatment with NaOH. The pulp obtained was bleached and acetylated, and subsequently membranes of this cellulose acetate were synthesized, incorporating oxidized lignin to these membranes in order to increase the metal retention capacity of them. The acetylated material was analyzed by IR, confirming acetylation. Degree of substitution was determined by volumetry, resulting in a diacetate to the MA I condition and a triacetate to MA II condition. It was observed that for the material with a lower degree of acetylation, it has better incorporation of oxidized lignins. SEM, showed membranes with dense structure. Tests were conducted to evaluate metal retention, and the average capacity of removal was 16% Cu(+2) in steady-state experiments.

Utilization of pineapple stem juice to enhance enzyme-hydrolytic efficiency for sugarcane bagasse after an optimized pre-treatment with alkaline peroxide

The enzymatic hydrolysis of sugarcane bagasse was investigated by treating a peroxide-alkaline bagasse with a pineapple stem juice, xylanase and cellulase. Pre-treatment procedures of sugarcane bagasse with alkaline hydrogen peroxide were evaluated and compared. Analyses were performed using 2(4) factorial designs, with pre-treatment time, temperature, magnesium sulfate and hydrogen peroxide concentration as factors. The responses evaluated were the yield of cellobiose and glucose released from pretreated bagasse after enzymatic hydrolysis. The results show that the highest enzymatic conversion was obtained for bagasse using 2% hydrogen peroxide at 60 degrees C for 16 h in the presence of 0.5% magnesium sulfate. Bagasse (5%) was treated with pineapple stem extract, which contains mixtures of protease and esterase, in combination with xylanase and cellulase. It was observed that the amount of glucose and cellobiose released from bagasse increased with the mixture of enzymes. It is believed that the enzymes present in pineapple extracts are capable of hydrolyze specific linkages that would facilitate the action of digesting plant cell walls enzymes. This increases the amount of glucose and other hexoses that are released during the enzymatic treatment and also reduces the amount of cellulase necessary in a typical hydrolysis. (C) 2010 Elsevier Ltd. All rights reserved.

Tick saliva induces regulatory dendritic cells: MAP-kinases and Toll-like receptor-2 expression as potential targets

Ticks (Acari: Ixodidae) are bloodsucking ectoparasitic arthropods of human and veterinary medical importance. Tick saliva has been shown to contain a wide range of bioactive molecules with vasodilatory, antihemostatic, and immunomodulatory activities. We have previously demonstrated that saliva from Rhipicephalus sanguineus ticks inhibits the maturation of dendritic cells (DCs) stimulated with LPS. Here we examined the mechanism of this immune subversion, evaluating the effect of tick saliva on Toll-like receptor (TLR)-4 signalling pathway in bone marrow-derived DCs. We demonstrated that R. sanguineus tick saliva impairs maturation of DCs stimulated with LIPS, a TLR-4 ligand, leading to increased production of interleukin (IL)-10 and reduced synthesis of IL-12p70 and TNF-alpha. The immunomodulatory effect of the tick saliva on the production of pro-inflammatory cytokines by DCs stimulated with LPS was associated with the observation that tick saliva inhibits the activation of the ERK 1/2 and p38 MAP kinases. These effects were independent of the expression of TLR-4 on the surface of DCs. Additionally, saliva-treated DCs also presented a similar pattern of cytokine modulation in response to other TLR ligands. Since the recent literature reports that several parasites evade immune responses through TLR-2-mediated production of IL-10, we evaluated the effect of tick saliva on the percentage of TLR-2(+) DCs stimulated with the TLR-2 ligand lipoteicoic acid (LTA). The data showed that the population of DCs expressing TLR-2 was significantly increased in DCs treated with LTA plus saliva. In addition, tick saliva alone increased the expression of TLR-2 in a dose- and time-dependent manner. Our data suggest that tick saliva induces regulatory DCs, which secrete IL-10 and low levels of IL-12 and TNF-alpha when stimulated by TLR ligands. Such regulatory DCs are associated with expression of TLR-2 and inhibition of ERK and p38, which promotes the production of IL-10 and thus down-modulates the host`s immune response, possibly favouring susceptibility to tick infestations. (C) 2009 Elsevier B.V. All rights reserved.

Alcohol Dependence: Analysis of Factors Associated with Retention of Patients in Outpatient Treatment

Aims: To identify factors associated with retention in treatment of alcohol-dependent individuals and to compare treatment retention between men and women. Methods: Analysis of the treatment attendance records and baseline characteristics of 833 men and 218 women who undertook to attend follow-up treatment in an alcoholism treatment centre. Results: Retention after 4 weeks of treatment is more likely to occur among those using adjuvant medication (the most frequent of which was disulfiram), those presenting severe alcoholism and those who are older and tend to be frequent drinkers. There was no gender difference regarding treatment retention. Conclusion: Such results suggest possibilities for developing specific strategies to reduce the risk of early dropout from treatment.

Structural and physicochemical characterization of RS prepared using hydrolysis and heat treatments of chickpea starch

The aim of this study was to evaluate the production and the structural and physicochemical properties of RS obtained by molecular mass reduction (enzyme or acid) and hydrothermal treatment of chickpea starch. Native and gelatinized starch were submitted to acid (2 M HCl for 2.5 h) or enzymatic hydrolysis (pullulanase, 40 U/g per 10 h), autoclaved (121 degrees C/30 min), stored under refrigeration (4 degrees C/24 h), and lyophilized. The hydrolysis of starch increased the RS content from 16% to values between 20 and 32%, and the enzymatic treatment of the gelatinized starch was the most efficient. RS showed an increase in water absorption and water solubility indexes due to hydrolytic and thermal process. The processes for obtaining RS changed the crystallinity pattern from C to B. Hydrolysis treatments caused an increase in relative crystallinity due to the greater retrogradation caused by the reduction in MW. RS obtained from hydrolysis showed a reduction in viscosity, indicating the rupture of molecules. The viscosity seemed to be inversely proportional to the RS content in the sample.

Effects of the herbicides acetochlor and metolachlor on antioxidant enzymes in soil bacteria

The aim of this study was to investigate the antioxidant responses of three bacteria (SD1. KD and K9) isolated from soil previously treated with the herbicides metolachlor and acetochlor. By 165 rRNA gene sequencing, we determined that SD1 is phylogenetically related to Enterobacter asburiae, while KD and K9 have divergent genomes that more closely resemble that of Enterobacter amnigenus. Decreased levels of lipid peroxidation were observed in SD1 and KD following treatment with 34 mM metolachlor or 62 mM acetochlor, respectively, indicating that both bacteria were able to adapt to an increase in ROS production. In the presence of 34 mM metolachlor or 62 mM acetochlor, all bacterial isolates exhibited increases in total catalase (CAT) activity (81% for SDI, 53% for KD and 59% for K9), whereas total SOD activity (assessed based on the profile and intensity of the bands) was slightly reduced when the bacteria were exposed to high concentrations of the herbicides (340 mM metolachlor or 620 mM acetochlor). This effect was due to a specific reduction in SOD IV (K9 and KD isolates) by 45% and 90%, respectively, and SOD V (SD1 isolate) isoenzymes by 60%. The most striking result was obtained in the SD1 isolate, where two novel isoenzymes of glutathione reductase (GR) that responded specifically to metolachlor were identified. In addition, acetochlor was shown to induce the expression of a new 57 kDa protein band in the K9 and KD isolates. The bacteria isolated from the herbicide-contaminated soil exhibited an efficient antioxidant system response at herbicide concentrations of up to 34 mM metolachlor or 62 mM acetochlor. These data suggest a mechanism for tolerance that may include the control of an imbalance in ROS production versus scavenging. The data suggest that specific isoenzymes of CAT and GR could be involved in this herbicide tolerance mechanism. (C) 2011 Elsevier Ltd. All rights reserved.

Influence of gamma radiation onto polymeric matrix with papain

Papain is a proteolytic enzyme that has been widely used as debridement agent for scars and wound healing treatment. However, papain presents low stability, which limits its use to extemporaneous or short shelf-life formulations. The purpose of this study was to entrap papain into a polymeric matrix in order to obtain a drug delivery system that could be used as medical device. Since these systems must be sterile, gamma radiation is an interesting option and presents advantages in relation to conventional agents: no radioactive residues are formed: the product can be sterilized inside the final packaging and has an excellent reliability. The normative reference for the establishment of the sterilizing dose determines 25 kGy as the inactivation dose for viable microorganisms. A silicone dispersion was selected to prepare membranes containing 2% (w/w) papain. Irradiated and non-irradiated membranes were simultaneously assessed in order to verify whether gamma radiation interferes with the drug-releasing profile. Results showed that irradiation does not affect significantly papain release and its activity. Therefore papain shows radioresistance in the irradiation conditions applied. In conclusion, gamma radiation can be easily used as sterilizing agent without affecting the papain release profile and its activity onto the biocompatible device is studied. (C) 2009 Elsevier Ltd. All rights reserved.

Preparation and characterization of ethanol-treated silk fibroin dense membranes for biomaterials application using waste silk fibers as raw material

The possibility of producing valued devices from low cost natural resources is a subject of broad interest. The present study explores the preparation and characterization of silk fibroin dense membranes using waste silk fibers from textile processing. Morphology, crystallinity, thermal resistance and cytotoxicity of membranes as well as the changes on the secondary structure of silk fibroin were analyzed after undergoing treatment with ethanol. Membranes presented amorphous patterns as determined via X-ray diffraction. The secondary structure of silk fibroin on dense membranes was either random coil (silk I) or p-sheet (silk II), before and after ethanol treatment, respectively. The sterilized membranes presented no cytotoxicity to endothelial cells during in vitro assays. This fact stresses the material potential to be used in the fabrication of biomaterials, as coatings of cardiovascular devices and as membranes for wound dressing or drug delivery systems. (C) 2010 Elsevier Ltd. All rights reserved.

Impact of cholesterol on ABC and SLC transporters expression and function and its role in disposition variability to lipid-lowering drugs

This report focuses on the effects of cholesterol on the expression and function of the ATP-binding cassette (ABCB1, ABCG2 and ABCC2) and solute-linked carrier (SLCO1B1 and SLCO2B1) drug transporters with a particular focus on the potential impact of cholesterol on lipid-lowering drug disposition. Statins are the most active agents in the treatment of hypercholesterolemia. However, considerable interindividual variation exists in the response to statin therapy. Therefore, it would be huge progress if factors were identified that reliably differentiate between responders and nonresponders. Many studies have suggested that plasma lipid concentrations can affect drug disposition of compounds, such as ciclosporin and amphotericin B. Both compounds are able to affect the expression and function of ABC transporters. Although still speculative, these effects might be owing to the regulation of drug transporters by plasma cholesterol levels. Studies with normo- and hyper-cholesterolemic individuals, before and after atorvastatin treatment, have demonstrated that plasma cholesterol levels are correlated with drug transporter expression, as well as being related to atorvastatin`s cholesterol-lowering effect. The mechanism influencing the correlation between cholesterol levels and the expression and function of drug transporters remains unclear. Some studies provide strong evidence that nuclear receptors, such as the pregnane X receptor and the constitutive androstane receptor, mediate this effect. In the near future, pharmacogenomic studies with individuals in a pathological state should be performed in order to identify whether high plasma cholesterol levels might be a factor contributing to interindividual oral drug bioavailability.

Mutagenicity and Antimutagenicity of Baccharis dracunculifolia Extract in Chromosomal Aberration Assays in Chinese Hamster Ovary Cells

Baccharis dracunculifolia De Candole (Asteraceae), a native plant from the Brazilian ""cerrado"", is widely used in folk medicine as an anti-inflammatory agent and for the treatment of gastrointestinal diseases. B. dracunculifolia has been described as the most important plant source of propolis in southeastern Brazil, which is called green propolis due to its color. The aim of the present study was to evaluate the mutagenic and antimutagenic effects of the ethyl acetate extract of B. dracunculifolia leaves (Bd-EAE) on Chinese hamster ovary cells. On one hand, the results showed a significant increase in the frequencies of chromosome aberrations at the highest Bd-EAE concentration tested (100 mu g/mL). On the other hand, the lowest Bd-EAE concentration tested (12.5 mu/mL) significantly reduced the chromosome damage induced by the chemotherapeutic agent doxorubicin. The present results indicate that Bd-EAE has the characteristics of a so-called Janus compound, that is, Bd-EAE is mutagenic at higher concentrations, whereas it displays a chemopreventive effect on doxorubicin-induced mutagenicity at lower concentrations. The constituents of B. dracunculifolia responsible for its mutagenic and antimutagenic effects are probably flavonoids and phenylpropanoids, since these compounds can act either as pro-oxidants or as free radical scavengers depending on their concentration.

Photoprotective potential of emulsions formulated with Buriti oil (Mauritia flexuosa) against UV irradiation on keratinocytes and fibroblasts cell lines

Considering the belief that natural lipids are safer for topical applications and that carotenoids are able to protect cells against photooxidative damage, we have investigated whether topical creams and lotions, produced with Buriti oil and commercial surfactants, can exert photoprotective effect against UVA and UVB irradiation on keratinocytes and fibroblasts. Cell treatment was divided into two steps, prior and after exposition to 30 min of UVA plus UVB radiation or to 60 min of UVA radiation. Emulsions prepared with ethoxylated fatty alcohols as surfactants and containing alpha-tocopherol caused phototoxic damage to the cells, especially when applied prior to UV exposure. Damage reported was due to prooxidant activity and phototoxic effect of the surfactant. Emulsions prepared with Sorbitan Monooleate and PEG-40 castor oil and containing panthenol as active ingredient, were able to reduce the damages caused by radiation when compared to non-treated cells. When the two cell lines used in the study were compared, keratinocytes showed an increase in cell viability higher than fibroblasts. The Buriti oil emulsions could be considered potential vehicles to transport antioxidants precursors and also be used as adjuvant in sun protection, especially in after sun formulations. (C) 2009 Elsevier Ltd. All rights reserved.

Lutein improves antioxidant defense in vivo and protects against DNA damage and chromosome instability induced by cisplatin

Lutein (LT) is the second most prevalent carotenoid in human serum, and it is abundantly present in dark, leafy green vegetables. The objectives of this study were to evaluate the genotoxicity and mutagenicity of LT, and its protective effects in vivo against DNA damage and chromosome instability induced by cisplatin (cDDP). For this purpose, we used the comet assay and micronucleus (MN) test, and we evaluated the antioxidant effects of LT by determination of enzymatic (catalase-CAT) and non-enzymatic (reduced glutathione-GSH) activity. Mice were divided into six groups: cDDP, mineral oil (OM), LT groups and LT + cDDP groups. To perform the MN test on peripheral blood (PB) cells, blood samples were collected before the first treatment (T0), and 36 h (T1) and 14 days (T2) after the first treatment. To perform the comet assay, blood samples were collected 4 h after the first and the last treatment. Oxidative capacity was analyzed in total blood that was collected 24 h after the last treatment, when bone marrow (BM) sample was also collected for the MN test. No genotoxic or mutagenic effects of LT were observed for the doses evaluated. We did find that this carotenoid was able to reduce the formation of crosslinks and chromosome instability induced by cDDP. No differences were observed in CAT levels, and LT treatment increased GSH levels compared with a negative control group, reinforcing the role of this carotenoid as an antioxidant.

The prediction of disease risk in genomic medicine

In recent years, the phrase 'genomic medicine' has increasingly been used to describe a new development in medicine that holds great promise for human health. This new approach to health care uses the knowledge of an individual's genetic make-up to identify those that are at a higher risk of developing certain diseases and to intervene at an earlier stage to prevent these diseases. Identifying genes that are involved in disease aetiology will provide researchers with tools to develop better treatments and cures. A major role within this field is attributed to 'predictive genomic medicine', which proposes screening healthy individuals to identify those who carry alleles that increase their susceptibility to common diseases, such as cancers and heart disease. Physicians could then intervene even before the disease manifests and advise individuals with a higher genetic risk to change their behaviour - for instance, to exercise or to eat a healthier diet - or offer drugs or other medical treatment to reduce their chances of developing these diseases. These promises have fallen on fertile ground among politicians, health-care providers and the general public, particularly in light of the increasing costs of health care in developed societies. Various countries have established databases on the DNA and health information of whole populations as a first step towards genomic medicine. Biomedical research has also identified a large number of genes that could be used to predict someone's risk of developing a certain disorder. But it would be premature to assume that genomic medicine will soon become reality, as many problems remain to be solved. Our knowledge about most disease genes and their roles is far from sufficient to make reliable predictions about a patient’s risk of actually developing a disease. In addition, genomic medicine will create new political, social, ethical and economic challenges that will have to be addressed in the near future.