First passage of an active particle in the presence of passive crowders.

We experimentally study the stochastic transport of a self-propelled camphor boat, driven by Marangoni forces, through a crowd of passive paper discs floating on water. We analyze the statistics of the first passage times of the active particle to travel from the center of a circular container to its boundary. While the mean times rise monotonically as a function of the covered area fraction φ of the passive paper discs, their fluctuations show a non-monotonic behavior - being higher at low and high value of φ compared to intermediate values. The reason is traced to an interplay of two distinct sources of fluctuations - one intrinsic to the dynamics, while the other due to the crowding.

Anti-Ascaris suum immunoglobulin Y as a novel biotechnological tool for the diagnosis of human ascariasis.

Human ascariasis is a neglected tropical disease of great relevance to public health and is considered the most frequent helminthiasis in poor regions. Accurately diagnosing this parasite has been challenging due to limitations of current diagnostic methods. Immunoglobulin Y (IgY) technology is a very effective alternative for the production of highly specific and profitable antibodies. This study aimed to produce and apply anti-Ascaris suum IgY antibodies in the immunodiagnosis of human ascariasis. Five immunizations comprising total saline extract from A. suum adult life forms were given at 14-day intervals to Gallus gallus domesticus hens of the Isa Brown line. Eggs and blood samples were collected weekly and fortnightly, respectively, to monitor the production of antibodies. The specificity of antibodies was confirmed by dot-blot, kinetic enzyme-linked immunosorbent assay (ELISA), avidity ELISA, immunoblotting and indirect immunofluorescence antibody tests. The application for disease diagnosis was performed through the detection of immune complexes in human serum samples by sandwich ELISA. Peaks of IgY anti-A. suum production occurred at weeks 6 and 8. IgY showed high avidity levels after the second dose of immunization, ranging from 64% to 93%, with a mean avidity index of 78.30%. Purified IgY recognized 12 bands of proteins from A. suum saline extract. Eggs, the uterine portion and cuticles of A. suum female adult are reactive in immunofluorescence. The detection of immune complexes showed diagnostic values of 80% sensitivity and 90% specificity. In conclusion, specific IgY have been shown to be a potential immunodiagnostic tool with promising future applications in human ascariasis.

Technical approaches to evaluate the surfactant-enhanced biodegradation of biodiesel and vegetable oils.

This research compared the effects of biosurfactant on the biodegradation of biodiesel and vegetable oils while validating two conceptually diverging methodologies. The two experimental setups were successfully modeled towards the effects of biosurfactants during biodegradation. We established the equivalence of both methodologies from the data output. As expected, the biosurfactants caused an increased oil uptake, thus increasing biodegradation performance. Cooking oils were favored by the microbial consortium as a carbon source when compared with biodiesel fuel, especially after use in food preparation. However, we found that biodiesel substrate standout with the highest biodegradation rates. Our results might indicate that a rapid metabolic change from the original compound initially favored biodiesels during the assimilation of organic carbon for a set specialized microbial inoculum. The data output was successfully combined with mathematical models and statistical tools to describe and predict the actual environmental behavior of biodiesel and vegetable oils. The models confirmed and predicted the biodegradation effectiveness with biosurfactants and estimated the required timeframe to achieve satisfactory contaminant removal.

Immune complex detection in saliva samples: an innovative proposal for the diagnosis of human strongyloidiasis.

Human strongyloidiasis is caused by helminth Strongyloides stercoralis. It has a worldwide distribution, often neglected and cause of severe morbidity. The parasitological diagnosis is hindered by the low and irregular amount of larvae in feces. The goal of the present study was to detect IgG and IgG immune complex using conventional serum samples and saliva as alternative samples. We collected samples from 60 individuals, namely: group I composed of 30 healthy individuals; and group II composed of 30 individuals eliminating S. stercoralis larvae in feces. We calculated the area under the curve, general index of diagnostic accuracy, Kappa index and determined the correlations between different diagnostic tests. The detection of IgG levels was performed by an immunoenzymatic assay with alkaline extract of S. venezuelensis larvae as antigen. Positivity of anti-S. stercoralis IgG in serum samples from group I was 3·3%, and from group II 93·3%. The detection of immune complex indicated that group I exhibited 3·3% and group II 56·7%. In the saliva samples, IgG detection was 26·7% for group I and 43·3% for group II. Immune complex was detected in 20% of group I, and 30% of group II. IgG immune complex in conventional serum samples and saliva as alternative samples can be considered biomarkers for the diagnosis of active strongyloidiasis.

Biosurfactants in cosmetic formulations: trends and challenges.

Cosmetic products play an essential role in everyone's life. People everyday use a large variety of cosmetic products such as soap, shampoo, toothpaste, deodorant, skin care, perfume, make-up, among others. The cosmetic industry encompasses several environmental, social and economic impacts that are being addressed through the search for more efficient manufacturing techniques, the reduction of waste and emissions and the promotion of personal hygiene, contributing to an improvement of public health and at the same time providing employment opportunities. The current trend among consumers is the pursuit for natural ingredients in cosmetic products, as many of these products exhibit equal, better or additional benefits in comparison with the chemical-based products. In this sense, biosurfactants are natural compounds with great potential in the formulation of cosmetic products given by their biodegradability and impact in health. Indeed, many of these biosurfactants could exhibit a "prebiotic" character. This review covers the current state-of-the-art of biosurfactant research for cosmetic purposes and further discusses the future challenges for cosmetic applications.

Usefulness of gel filtration fraction as potential biomarker for neurocysticercosis in serum: towards a new diagnostic tool.

There is an increasing interest in improving neurocysticercosis (NCC) diagnosis through the search of new and alternative antigenic sources, as those obtained from heterologous antigens. The aim of this study was to obtain potential biomarkers for NCC diagnosis after gel filtration chromatography [gel filtration fraction (GFF)] from the total saline extract (SE) from Taenia saginata metacestodes, followed by protein identification and application in immunodiagnostic. SE and GFF proteic profiles were characterized in gel electrophoresis, and diagnostic performance was verified by testing 160 serum samples through enzyme-linked immunosorbent assay and immunoblotting. Sensitivity (Se), specificity (Sp) and other diagnostic parameters were calculated. Polypeptides of interest in the diagnosis of human NCC present at GFF were analysed by mass spectrometry (MS) and B-cell epitopes were predicted. GFF had the best diagnostic parameters: Se 93·3%; Sp 93%; AUC 0·990; LR+ = 13·42 and LR- = 0·07, and proved to be useful reacting with serum samples in immunoblotting. Proteic profile ranged from 64 to 68 kDa and enolase and calcium binding protein calreticulin precursor were identified after MS. The enolase and calcium-binding protein calreticulin precursor showed 18 and 10 predicted B-cell epitopes, respectively. In conclusion we identified important markers in the GFF with high efficiency to diagnose NCC.

Diagnosis of the pinworm Syphacia muris in the Wistar rat Rattus norvegicus.

This study aimed to compare three qualitative parasitological methods for the diagnosis of Syphacia muris infection in 30 Wistar rats (Rattus norvegicus) infected naturally. Methods of spontaneous sedimentation (Hoffman, Pons and Janer, or HPJ) and spontaneous flotation (Willis) for faecal samples and a method of taping (Graham) were performed and compared. The Graham and Willis methods were more sensitive than the HPJ method (P< 0.05). The Graham method was able to detect S. muris eggs in 100% of the samples. Eggs were detected in 83% and 60% of the samples using the Willis and HPJ methods, respectively. Method choice is important for screening for parasites of rats kept under laboratory conditions, as accurate diagnosis helps prevent future environmental contamination and infection. We concluded that the Graham method was the most efficient of those tested in this study for detection of S. muris infection in rats. This method is also rapid, inexpensive and practical, and should be implemented as a necessary measure for infection control.

Specific IgG and immune complex responses to parthenogenetic females and eggs of nematode Strongyloides venezuelensis for the diagnosis of immunosuppression in infected rats.

In the present study, antigens from parthenogenetic females and eggs of Strongyloides venezuelensis, or anti-parthenogenetic-female and anti-egg antigens were used to detect specific IgG and immune complex responses, respectively. Serum samples from experimentally infected immunocompetent and immunosuppressed rats were analysed on days 5, 8, 13 and 21 post-infection (dpi). An enzyme-linked immunosorbent assay (ELISA) was performed using alkaline parasite extract for specific IgG detection, and anti-parthenogenetic-female or anti-egg antigens for immune complex detection. The data were analysed using analysis of variance (ANOVA), followed by a Bonferroni test. When parthenogenetic female or egg extracts were used as antigens, specific IgGs were not detected in either immunocompetent or immunosuppressed rats. When anti-parthenogenetic-female or anti-S. venezuelensis-eggs were used, immune complexes were detected for the duration of the infection in immunosuppressed animals and were only detected between 5 and 13 dpi in immunocompetent animals. The duration of infection was not significantly different between the immunocompetent and immunosuppressed groups when anti-parthenogenetic-female or anti-S. venezuelensis-eggs were used. Parthenogenetic female extracts yielded significant differences between antibody and immune complex responses in immunocompetent rats from 5 to 13 dpi, but only on day 5 dpi in immunosuppressed rats. Exposure to S. venezuelensis egg extract yielded significant differences in both antibody and immune complex detection between immunocompetent and immunosuppressed rats for the duration of the infection. In conclusion, ELISA using alternative antigens may be a successful strategy for identifying immune complexes in serum samples and diagnosing active strongyloidiasis, particularly under conditions of immunosuppression.

Diagnosis of the strongyloid nematode Strongyloides venezuelensis in experimentally infected rats.

Strongyloides venezuelensis is an intestinal nematode of rats, frequently used as a model for studying human and animal strongyloidiasis. In the present study, we evaluated parasitological, serological and molecular methods for the diagnosis of experimental S. venezuelensis in rats, Rattus norvegicus. Blood and faecal samples were collected and analysed up to 60 days post infection (pi) with adult worm recovery occurring from 5 to 45 days pi. Using an enzyme-linked immunosorbent assay (ELISA), serum levels of IgG antibodies increased up to 28 days pi, thereafter decreasing by day 60 pi. Polymerase chain reaction (PCR) assays detected S. venezuelensis DNA in faecal samples of rats from 5 to 21 days pi. The present study therefore represents the first step towards improving the diagnosis of experimental strongyloidiasis.

Optimization of liquid-liquid extraction of biosurfactants from corn steep liquor.

In this work, the optimization of the operational conditions for the chloroform-based extraction of surface-active compounds from corn steep liquor (CSL) was carried out and the nutritional properties of the remnant aqueous phase (CSL-less biosurfactant) was evaluated as microbial fermentation medium. The optimal conditions to obtain biosurfactants from CSL were as follows: chloroform/CSL ratio 2 (v/v), 56 °C at extraction times >30 min. At the optima conditions, 100 % of biosurfactant extract can be obtained from CSL, obtaining 12.0 ± 0.5 g of biosurfactant extract/Kg of CSL. The critical micelle concentration (CMC) of the biosurfactant extract was 399.4 mg L(-1). This value is similar to the CMC of cetrimonium bromide (CTAB), a cationic surfactant used in the formulation of nanoparticles. The extraction of biosurfactant can be also carried out at room temperature although in this case, the extraction yield decreased about 15 %. The extraction of surface-active compounds from agroindustrial streams can suppose important advances for the bio-based surfactants industry. Biosurfactants obtained in this work are not only more eco-friendly than chemical detergents but also can be cost competitive with its chemical counterparts. Furthermore, after the extraction of surface-active compounds, CSL-less biosurfactant was found to be suitable as nutritional supplement for lactic acid bacteria, maintaining its nutritional properties in comparison with regular CSL.

[Poland's syndrome and free autologous fat grafts]. / Síndrome de Poland e injertos libres de grasa autóloga.

OBJECTIVE: To evaluate the final reconstructive results in 6 cases of female Poland syndrome treated in a first stage with an anatomical high cohesive breast implants and in a second stage with free autologous fat grafts. METHODS: Six females were submitted to bilateral breast reconstruction. The reconstruction was done using anatomical breast implants as first step and after 11 to 18 months the free autologous fat grafting using the Coleman technique as well as treating the contralateral breast to achieve a better symmetry and volume. Photographies taken pre and postoperatively and the Foucras Classification were used to determine volume. Four months after the last surgery the patients answered a satisfaction questionnaire. RESULTS: In all 6 patients there was an improvement of the thoracic contour a year after the last surgery in terms of volume, projection and width of the breast. CONCLUSIONS: The use of free autologous fat grafts improves the results in cases of Poland's syndrome previously treated with breast implants making possible to correct the anterior axillary fold, projection and symmetry with a versatile method, with a low morbidity rate, allowing for a personalized treatment.

Modelling and impact of tensiometer plate geometry and sample volume on biosurfactant surface activity assessment.

Biosurfactants are molecules with hydrophilic and hydrophobic moieties with the capacity to reduce the surface tension of water. Given the limited quantity of biosurfactant extracts in laboratories, it is recommended to use equipment that requires minimal sample quantities for detecting the presence of biosurfactants. In this work, commercial glycolipids biosurfactants (rhamnolipids or sophorolipids) were diluted in water and subjected to different analyses to obtain their minimum surface tension (ST) reduction and their critical micellar concentration (CMC). The independent variables of the study were: the geometry of platinum plate (rectangular or cylindrical), the sample volume (2, 4 and 20 mL) and the container material consisting of either glass or polytetrafluoroethylene (PTFE). The variation of ST with biosurfactant concentration was studied based on the isotherm model proposed by Li & Lu. It was observed that the profile of ST values did not vary so much using the different independent variables described, observing that platinum rectangular plate can be used for volumes of 4 mL biosurfactants instead of cylindrical plate usually recommended for volumes lower than 20 mL, the container material was also not significant based on the Pearson and Spearman statistical treatment. Moreover, well-fitting regression model results were obtained for a non-commercial biosurfactant extract obtained from a residual stream of the dairy industry, predicting values close to the observed data.

Effect of calcium-enriched microalgae extract on mitigating saline stress in papaya seedlings.

The papaya (Carica papaya L.) is among the mainly fruit species produced in tropical and subtropical climate. The salinity of water in agricultural areas is considered a limiting factor for the expansion of papaya. This study aimed to evaluate calcium-enriched microalgae extract (EMa-Ca) as an attenuator of saline stress in irrigation water on the growth and physiology of Formosa papaya seedlings, hybrid Tainung. The experiment was conducted in a protected environment, with treatments distributed in a 5 × 2 factorial scheme, comprising five electrical conductivities of irrigation water (0.50; 1.10; 2.50; 3.90 and 4.50 dSm-1) with the presence and absence of EMa-Ca in the substrate. Evaluated characteristics were: plant height, number of leaves, stem diameter, leaf area, dry masses weight of roots, aboveground parts and total. Gas exchanges and chlorophyll indices (a, b and total) were also evaluated. The application of EMa-Ca resulted in an increase of 6.05% in height and 6.33% in trunk diameter. The number of leaves decreased with an increase in electrical conductivity, and the leaf area was reduced by 33%. All seedling dry masses showed greater declines in the absence of EM-Ca. The EMa-Ca increased net photosynthesis, CO2 concentration, transpiration and stomatal conductance by 39.13%, 30.43%, 38.88% and 42.85%, respectively. For chlorophyll without the use of EMa-Ca, a decrease rate of 1.21%, 0.41% and 1.62% was observed for Chla, Chlb and Chlt, respectively. Therefore, the EMa-Ca application (1.0 ml/L) significantly enhance the vegetative development, gas exchanges, and chlorophyll indices of papaya seedlings under saline stress conditions.

Ion-exchange protocol to obtain antigenic fractions with potential for serodiagnosis of strongyloidiasis.

The aim of this study was to fractionate and partially characterize the antigenic extract of filariform larvae of Strongyloides venezuelensis in ion-exchange resin diethylaminoethyl sepharose (DEAE), to obtain antigenic fractions potentially applicable in immunoassays. Somatic antigen (SA) and its fractions DEAE S1 and DEAE S2 - which interacted with the resin - were evaluated by 1-dimensional electrophoresis to obtain protein profiles. SA and its fractions were tested in serum samples for IgG detection by ELISA. Serum samples (n = 155) were analysed: 50 from strongyloidiasis patients (G1), 55 from patients with other parasitic infections (G2) and 50 from healthy volunteers. Sensitivity (Se), specificity (Sp), area under curve (AUC) and likelihood ratios (LR) were calculated. The DEAE S2 fraction provided a high diagnostic value for IgG detection (Se 92·0%, Sp 91·4%, AUC 0·981, LR+ 10·75, LR - 0·09). In conclusion, the DEAE S2 fraction would probably be a source of immunodominant polypeptides for IgG detection in human strongyloidiasis serodiagnosis.

Evaluation of biosurfactant obtained from Lactobacillus pentosus as foaming agent in froth flotation.

This study analyzes the kinetics of sediment sorption on two chemical surfactants (Tween 20 and SDS) and a biotechnologically produced surfactant (obtained from Lactobacillus pentosus). Biosurfactants were produced by fermentation of hemicellulosic sugars from vineyard pruning waste supplied as a substrate to L. pentosus. Results obtained showed that almost no SDS was adsorbed onto the sediments, whereas Tween 20 and biosurfactants from L. pentosus were absorbed after a few minutes. Kinetic models revealed that adsorption of surfactant onto riverbed sediments is governed not only by an intra-particle diffusion model (evaluated by the Weber and Morris model), but also by surface reaction models (evaluated by first, second, third order equations and Elovich equation), showing the best fit when employing the Elovich model. The adsorption properties showed by biosurfactant from L. pentosus onto sediments present it as a potential foaming agent in froth flotation.

F-actin accumulates in the vulva of female Strongyloides venezuelensis.

Little is known about the actin cytoskeleton architecture in female Strongyloides venezuelensis and thus to investigate the distribution and concentration of actin, female worms were labelled with phalloidin-rhodamine and visualized under confocal microscopy. Our results demonstrate that filamentous actin accumulates in the vulva and the concentration of F-actin at this site suggests its important role, especially during oviposition, in the life cycle of S. venezuelensis.

Purification of lipopeptide biosurfactant extracts obtained from a complex residual food stream using Tricine-SDS-PAGE electrophoresis.

Protocols to identify lipopeptide biosurfactant extracts contained in complex residual streams are very important, as fermented agri-food matrices are potential sources of these valuable compounds. For instance, corn steep liquor (CSL), a secondary stream of the corn wet-milling industry, is composed of a mixture of microbial metabolites, produced during the corn steeping process, and other natural metabolites released from corn, that can interfere with the purification and analysis of lipopeptides. Electrophoresis could be an interesting technique for the purification and further characterization of lipopeptide biosurfactant extracts contained in secondary residual streams like CSL, but there is little existing literature about it. It is necessary to consider that lipopeptide biosurfactants, like Surfactin, usually are substances that are poorly soluble in water at acidic or neutral pH, forming micelles what can inhibit their separation by electrophoresis. In this work, two lipopeptide biosurfactant extracts obtained directly from CSL, after liquid-liquid extraction with chloroform or ethyl acetate, were purified by applying a second liquid extraction with ethanol. Following that, ethanolic biosurfactant extracts were subjected to electrophoresis under different conditions. Lipopeptides on Tricine-SDS-PAGE (polyacrylamide gels) were better visualized and identified by fluorescence using SYPRO Ruby dye than using Coomassie blue dye. The matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) analysis of lipopeptide isoforms separated by electrophoresis revealed the presence of masses at 1,044, 1,058, and 1,074 m/z, concluding that Tricine-SDS-PAGE electrophoresis combined with MALDI-TOF-MS could be a useful tool for purifying and identifying lipopeptides in complex matrices.

Potentially toxic elements capture by an active living wall in indoor environments: Effect of species in air phytoremediation.

Indoor air pollution is a serious health problem throughout the world. Plants are known to be able to reduce the effect of air pollution and improve indoor air quality (IAQ). The aim of the present study was to compare the effectiveness of four plant species (Tradescantia zebrina hort. ex Bosse, Philodendron scandens K. Koch & Sello, Ficus pumila L. and Chlorophtytum comosum (Thunb.) Jacques) planted in an active living wall (ALW) for capturing particle pollutants. The ALW was introduced in a glass chamber and exposed to large (10-40 µm) and fine (1.2-10 µm) airborne particles containing a fixed concentration of potentially toxic elements (Al, B, Cd, Co, Cr, Cu, Ni and Pb). The surface particle deposition (sPM) was estimated in the leaves from the four species and the potentially toxic element concentration in the particulate matter (PM) was measured in plants, medium culture and in the ALW support system. The distribution of different particle size fractions differed between species. The capacity to trap particles on leaf surfaces was similar among the species (4.7-13 ng cm-2) except when comparing Tradescantia and Chlorophytum with Ficus, being higher in the latter species. Differences in toxic elements accumulation capacity were observed between species depending on the elements considered. The percentage of reduction in indoor pollution using an ALW was in a range of 65-79% being similar between species. Plants were the most important component of the ALW in terms of accumulation of indoor potentially toxic elements. The data presented here could be used to model the effectiveness of ALW systems schemes in improving IAQ.

Use of larval, parasitic female and egg antigens from Strongyloides venezuelensis to detect parasite-specific IgG and immune complexes in immunodiagnosis of human strongyloidiasis.

The aim of this study was to use larval, parasitic female and egg antigens from Strongyloides venezuelensis to detect parasite-specific IgG and immune complexes in human serum samples by enzyme-linked immunosorbent assay (ELISA). In total, 95 serum samples were analysed, consisting of 30 patients harbouring S. stercoralis larvae, 30 healthy subjects and 35 patients with other parasites. Sensitivity, specificity and diagnostic efficiency were calculated. A significant statistical difference was found in the detection of immune complexes and antibodies in patients harbouring S. stercoralis larvae from larval and eggs antigens, with higher positivity using larval antigen. The larval antigen showed the highest values for sensitivity, specificity and diagnostic efficiency in ELISA from detection of immune complexes. For the first time we used IgG anti-larvae, IgG anti-parasitic females or IgG anti-eggs for immune complex detection. We concluded that the association of antibody and immune complex detection could be used in the diagnosis of human strongyloidiasis.