Lower breast cancer survival among Black women in Brazil: a population-based retrospective study.

OBJECTIVES: To analyze the rates of breast cancer survival among Black and White women according to age and stage at diagnosis. STUDY DESIGN: A retrospective cohort study. METHODS: The study examined women registered in the population-based cancer registry of Campinas in 2010-2014. The primary variable was the declared race (White or Black). Other races were excluded. Data were linked with the Mortality Information System, and missing information was accessed by active search. Overall survival (OS) was calculated by the Kaplan-Meier method, comparisons were done by chi-squared tests, and hazard ratios were examined by Cox regression. RESULTS: The total numbers of new cases of staged breast cancer among Black and White women were 218 and 1522 cases, respectively. The rates of stages III/IV were 35.5% among White women and 43.1% among Black women (P = 0.024). The frequencies among White and Black women under 40 years old were 8.0% and 12.4% (P = 0.031), 19.6% and 26.6% (P = 0.016) for ages of 40-49 years, and 23.8% and 17.4% (P = 0.037) for ages of 60-69 years, respectively. The mean OS was 7.5 years (7.0; 8.0) among Black women and 8.4 years (8.2; 8.5) among White women. The 5-year OS was 72.3% among Black women and 80.5% among White women (P = 0.001). Black women had an age-adjusted risk of death that was 1.7 times higher (1.33; 2.20). The risk was 6.4 times higher for diagnoses in stage 0 (1.65; 24.90) and 1.5 times for diagnoses in stage IV (1.04; 2.17). CONCLUSION: The 5-year OS for women with breast cancer was significantly lower among Black women than White women. Black women were more frequently diagnosed in stages III/IV, and their age-adjusted risk of death was 1.7 times higher. Differences in access to care may explain these differences.

Transport properties of n-ethylene glycol aqueous solutions with focus on triethylene glycol-water.

Soret effect and diffusion in triethylene glycol (TEG)-water mixtures were investigated as a function of concentration at 25 °C by means of optical digital interferometry, with the use of a classical Soret cell. Diffusion D, thermal diffusion DT, and Soret ST coefficients are described for the full concentration range and an analysis is made individually for TEG-water mixture and within a series of n-ethylene glycol (n-EG) aqueous systems. All coefficients decrease with increasing the concentration of TEG and n-EG. ST shows a change of sign with concentration, and this change is directly related to the ability of the n-EG molecule to establish hydrogen bonding with water. Diffusion and thermal diffusion coefficients present a plateau behavior with increasing concentration, showing the occurrence of changes in the preferential interactions in aqueous solution with concentration and meaning that, at high TEG composition, ether oxygens can be involved in the molecular interactions.

Microbiological, immunological, and histological changes in the gut of Salmonella Enteritidis-challenged rats fed goat cheese containing Lactobacillus rhamnosus EM1107.

Cheeses are able to serve as suitable matrices for supplying probiotics to consumers, enabling appropriate conditions for bacteria to survive gastric transit and reach the gut, where they are assumed to promote beneficial processes. The present study aimed to evaluate the microbiological, immunological, and histological changes in the gut of Salmonella Enteritidis-challenged rats fed goat cheese supplemented with the probiotic strain Lactobacillus rhamnosus EM1107. Thirty male albino Wistar rats were randomly distributed into 5 experimental groups with 6 animals each: negative (NC) and positive (PtC) control groups, control goat cheese (CCh), goat cheese added with L. rhamnosus EM1107 (LrCh), and L. rhamnosus EM1107 only (EM1107). All animals, except NC group were challenged with Salmonella Enteritidis (109 cfu in 1 mL of saline through oral gavage). Microbial composition was assessed with high-throughput 16S rRNA sequencing by means of Illumina MiSeq (Illumina, San Diego, CA). Nuclear factor kappa B (NF-κB) from the animal cecum tissue was determined by real-time PCR and interleukins (TNF-α, IL-1ß, IL-10, and IFN-γ) by means of ELISA. Myeloperoxidase and malondialdehyde levels were determined biochemically. The administration of the L. rhamnosus EM1107 probiotic strain, either as a pure culture or added to a cheese matrix, was able to reduce Salmonella colonization in the intestinal lumen and lessen tissue damage compared with rats from PtC group. In addition, the use of cheese for the probiotic strain delivery (LrCh) was associated with a marked shift in the gut microbiota composition toward the increase of beneficial organisms such as Blautia and Lactobacillus and a reduction in NF-κB expression. These findings support our hypothesis that cheeses might be explored as functional matrices for the efficacious delivery of probiotic strains to consumers.

The cis-encoded antisense RNA IsrA from Salmonella Typhimurium represses the expression of STM0294.1n (iasE), an SOS-induced gene coding for an endoribonuclease activity.

Toxin-antitoxin systems are known to be involved in many bacterial functions that can lead to growth arrest and cell death in response to stress. Typically, toxin and antitoxin genes of type I systems are located in opposite strands, where the antitoxin is a small antisense RNA (sRNA). In the present work we show that the sRNA IsrA from Salmonella Typhimurium down-regulates the expression of its overlapping gene STM0294.1n. Multiple sequence alignment and comparative structure analysis indicated that STM0294.1n belongs to the SymE toxin superfamily, and the gene was renamed iasE (IsrA-overlapping gene with similarity to SymE). The iasE expression was induced in response to mitomycin C, an SOS-inducing agent; conversely, IsrA overexpression repressed the iasE expression even in the presence of mitomycin C. Accordingly, the inactivation of IsrA with an anti-IsrA RNA expressed in trans abrogated the repressive effect of IsrA on the iasE expression. On the other hand, iasE overexpression, as well as the blockage of the antisense IsrA function, negatively affected bacterial growth, arguing for a toxic effect of the iasE gene product. Besides, a bacterial lysate obtained from the iasE-overexpressing strain exhibited endoribonuclease activity, as determined by a fluorometric assay based on fluorescent reporter RNAs. Together, these results indicate that the IasE/IsrA pair of S. Typhimurium constitutes a functional type I toxin-antitoxin system.

Suicide risk in people living with AIDS/HIV: the effect of childhood trauma is mediated by mental disorders and social vulnerability.

Suicide is an important problem in people living with HIV/AIDS (PLWHA). The importance of mental disorders and social vulnerability on suicidal behaviors is described in the literature; however, the impact of childhood traumatic events in this scenario is not clear. The aim of this study was to verify the mediation effect of mental disorder comorbidities and social vulnerability in association with childhood trauma intensity and suicide risk level. This cross-sectional study of HIV-positive outpatients was conducted in a specialized care service in the city of Pelotas in Southern Brazil. Sociodemographic data and HIV-related information were collected and the Childhood Trauma Questionnaire was applied. A total of 364 patients underwent psychiatric evaluation using MINI Plus including module C of suicide risk severity. Suicide risk was present in 39.3% of the sample. The relation between childhood traumatic events and the level of suicide risk is mediated by mental disorder comorbidities and socioeconomic vulnerability. Specific psychosocial interventions in PLWHA should consider the potential role of abusive traumatic experiences in the current mental health conditions and suicidal behaviors.

Nanoparticles Based on Novel Carbohydrate-Functionalized Polymers.

Polymeric nanoparticles can be used for drug delivery systems in healthcare. For this purpose poly(lactic-co-glycolic acid) (PLGA) and poly(ethylene glycol) (PEG) offer an excellent polymeric matrix. In this work, PLGA and PEG polymers were functionalized with coumarin and carbohydrate moieties such as thymidine, glucose, galactose, and mannose that have high biological specificities. Using a single oil in water emulsion methodology, functionalized PLGA nanoparticles were prepared having a smooth surface and sizes ranging between 114-289 nm, a low polydispersity index and a zeta potential from -28.2 to -56.0 mV. However, for the corresponding PEG derivatives the polymers obtained were produced in the form of films due to the small size of the hydrophobic core.

Distal radius and tibia bone microarchitecture impairment in female patients with diffuse systemic sclerosis.

Radius and tibia bone microarchitecture, analyzed through a high-resolution peripheral quantitative computed tomography, were significantly impaired in female patients with diffuse systemic sclerosis compared with healthy controls. Acroosteolysis, quality of life-grip strength, hand disability, and disease duration were significantly associated with this bone deterioration. INTRODUCTION: The effect of diffuse systemic sclerosis (dSSc) on the bone is not completely understood. The objective of this study was to analyze the volumetric bone mineral density (vBMD), microarchitecture, and biomechanical parameters at the distal radius and tibia using high-resolution peripheral quantitative computed tomography (HR-pQCT, XtremeCT) in female patients with dSSc and identify clinical and laboratory variables associated with these parameters. METHODS: Thirty-eight women with dSSc and 76 healthy controls were submitted to HR-pQCT at the distal radius and tibia. Clinical and laboratory findings, bone mineral density(BMD), nailfold capillaroscopy (NC), total passive range of motion(ROM), and quality of life (health assessment questionnaire-HAQ) were associated with HR-pQCT (Scanco Medical AG, Brüttisellen, Switzerland) parameters. Multiple linear regression models adjusted for clinical and laboratory variables, ROM and HAQ, were performed. RESULTS: Density, microarchitecture, and biomechanical parameters at the distal radius and tibia were significantly impaired in dSSc patients compared with healthy controls (p < 0.001). Multiple linear regression models showed that lower trabecular density (Tb.vBMD) (radius R2 = 0.561, p = 0.002; and tibia R2 = 0.533, p = 0.005), and lower trabecular number (Tb.N) (tibia R2 = 0.533, p = 0.005) were significantly associated with acroosteolysis. Higher trabecular separation (Tb.Sp) was associated with disease duration and higher HAQ-grip strength (radius R2 = 0.489, p = 0.013), while cortical density (Ct.vBMD) was associated with ROM (radius R2 = 0.294, p = 0.002). CONCLUSION: Bone microarchitecture in patients with dSSc, analyzed through HR-pQCT, showed impairment of trabecular and cortical bone at distal radius and tibia. Variables associated with hand involvement (acroosteolysis, quality of life-grip strength, and ROM) and disease duration may be considered prognostic factors of this bone impairment.

Experimental Observation of Proton Bunch Modulation in a Plasma at Varying Plasma Densities.

We give direct experimental evidence for the observation of the full transverse self-modulation of a long, relativistic proton bunch propagating through a dense plasma. The bunch exits the plasma with a periodic density modulation resulting from radial wakefield effects. We show that the modulation is seeded by a relativistic ionization front created using an intense laser pulse copropagating with the proton bunch. The modulation extends over the length of the proton bunch following the seed point. By varying the plasma density over one order of magnitude, we show that the modulation frequency scales with the expected dependence on the plasma density, i.e., it is equal to the plasma frequency, as expected from theory.

Advances, challenges and opportunities for point-of-need screening of mycotoxins in foods and feeds.

The assurance of food and feed safety, including the identification and effective monitoring of multiple biological and chemical hazards, is a major societal challenge, given the increasing pace at which food commodities are demanded, produced and traded across the globe. Within this context, mycotoxins are globally widespread secondary fungal metabolites, which can contaminate crops either in the field or during storage and have serious human and animal health impacts such as carcinogenic, teratogenic and hepatotoxic effects. Therefore, their presence in a wide range of foods and feeds is strictly regulated, particularly in the European Union. In order to perform effective and routine monitoring of mycotoxin levels in the field prior to further processing, during transport or during processing, rapid, simple, portable and sensitive means of screening of regulated mycotoxins are in high demand. This review focuses on (1) discussing the relevance of mycotoxins and the standard approaches for their sampling and monitoring; and (2) compiling and discussing recent advances in miniaturized analytical tools for mycotoxin detection. This provides insights into current research efforts and opportunities to develop a truly integrated and fit-for-purpose analytical tool, suitable for use at critical points of the food, feed and raw material processing and distribution chains.

Plasma level of club-cell (CC-16) predicts outcome in amyotrophic lateral sclerosis.

OBJECTIVES: The club cell protein (CC-16) is a biomarker associated with respiratory distress and pulmonary inflammation. We evaluated CC-16 as a candidate biomarker for respiratory failure in amyotrophic lateral sclerosis (ALS). MATERIALS AND METHODS: We studied 81 ALS patients and 30 matched controls. We used an ALS-related measure of functional capacity, and tested forced vital capacity (FVC) and the amplitude of the diaphragmatic response by phrenic nerve stimulation (PhrenAmpl). Plasma CC-16 levels were measured in venous blood. Kaplan-Meier survival curves were plotted to evaluate risk to non-invasive ventilation and death in patients with abnormal CC-16 levels. RESULTS: CC-16 levels were significantly raised in ALS patients (10.56 ng/mL ± 6.84 vs 8.34 ng/mL ± 3.10, P = .02), and in 17% of them, CC-16 level was above the upper cutoff value (mean + 2.5SD). CC-16 levels did not correlate with age, onset region, disease duration, functional status, FVC, and PhrenAmpl. In patients with increased CC-16 level, the risk of non-invasive was greater in the following 6 months (P = .01) and tended to have higher mortality in the following 30 months (P = .07). CONCLUSIONS: We propose that increased CC-16 levels is a marker of lung inflammatory response that associated with ventilatory insufficiency are related to impending respiratory failure, not fully predicted by conventional respiratory tests. The latter are limited by the moment of testing.

The application of microbeads to microfluidic systems for enhanced detection and purification of biomolecules.

This paper describes microbead-based microfluidic systems. Several aspects of bead assays in microfluidics make them advantageous for bioassays in simple microchannels, including enhanced surface-to-volume ratio, improved molecular recognition reaction efficiency, and the wide range of surface functionalization available with commercial microbeads. Two-level SU-8 molds are used to fabricate PDMS microchannels that can hydrodynamically trap different types of microbeads, with characteristic dimensions of tens of microns. The use of these microbead-based microfluidic systems in the biosensing of antibodies, toxins and nucleic acids, as well as in antibody purification will be presented and discussed in this paper.

Clinical and dermoscopic features of genital pigmented Bowen disease.

Pigmented Bowen disease (pBD) is an uncommon variant of squamous cell carcinoma in situ. Sometimes it can show clinical and dermoscopic features that are seen in other pigmented lesions of the skin and mucosa, making the diagnosis difficult. We report six cases of pBD occurring on the anogenital area, and discuss the importance of dermoscopy for improving the diagnostic accuracy in pBD.

Spatial distribution and risk factors for equine infectious anaemia in the state of Mato Grosso, Brazil.

The prevalence of equine infectious anaemia (EIA) in the three biomes of the state of Mato Grosso (Amazon, Cerrado and Pantanal) was estimated. Serum samples were collected from 3,858 equines in 1,067 herds between Septemberand December 2014. The agar gel immunodiffusion (AGID) assay was used to detect EIA virus antibodies, and if a herd contained a seropositive animal itwas classified as a focus. The prevalence rates were 17.2% (95% confidence interval [CI]: 14.9-19.8%) for herds and 6.6% (95% CI: 5.8-7.5%) for animals. The Pantanal region showed the highest prevalence rates: 36.1% (95% CI: 30.8-41.7%) for herds and 17.0% (95% CI: 14.7-19.6%) for animals. The spatial distribution of relative risk was calculated according to the kernel density, which revealed three major clusters with the highest prevalence rates occurring in the north-western(Amazon biome), north-eastern (Cerrado biome) and southern (Pantanal biome)regions. A high spatial correlation was found among ranches, with high intra-herd prevalence rates located in the Amazon and Cerrado biomes, but the highest spatial correlation with EIA foci was found in the Pantanal biome. Variables related to ranch management, reflecting human influence, were associated with positive equines. Based on the results, it can be concluded that EIA is present in all biomes of the state, and that the risk factors are associated with human interference in the transmission process. Given this situation, the EIA control programme should be re-evaluated and more prophylactic measures should be adopted to control the disease.

Les auteurs présentent les résultats d'une estimation de la prévalence de l'anémie infectieuse des équidés (AIE) dans les trois biomes de l'état du Mato Grosso (l'Amazonie, le Cerrado et le Pantanal) réalisée de septembre à décembre2014 à partir d'échantillons de sérum collectés chez 3 858 équidés dans1 067 troupeaux. La méthode d'immunodiffusion sur gélose était utilisée pour détecter les anticorps anti-AIE. En cas de test positif chez un individu, le troupeau était classé comme un foyer. La prévalence par troupeau était de 17,2 % (intervalle de confiance à 95 % [IC 95 %] de 14,9 à 19,8) tandis que la prévalence individuelle était de 6,6 % (IC 95 % de 5,8 à 7,5). La prévalence la plus élevée était enregistrée dans la région du Pantanal : 36,1 % (IC 95 % de 30,8 à 41,7) par troupeaux et17,0 (IC 95 % de 14,7 à 19,6) à l'échelle des individus. La distribution spatiale du risque relatif estimée par noyau montre trois grappes de prévalence élevée dans le nord-ouest (biome de l'Amazonie), le nord-est (biome du Cerrado) et le sud (biome du Pantanal). Si une corrélation spatiale forte est observée dans les élevages des biomes de l'Amazonie et du Cerrado où la prévalence intra-troupeau est élevée, la corrélation spatiale la plus élevée avec les foyers d'AIE se trouve dans le biome du Pantanal. Une association a été constatée entre les équidés testés positifs et les variables descriptives liées aux pratiques d'élevage, ce qui traduit l'importance de l'influence humaine. À partir de ces résultats, on peut conclure que l'AIE est présente dans l'ensemble des biomes de l'état et que les facteurs de risque sont associés à l'interférence humaine dans le processus de transmission. Ainsi, une réévaluation du programme de lutte contre l'AIE serait indiquée avec plus de mesures prophylactiques afin de contrôler la maladie.

Los autores describen el proceso seguido para estimar la prevalencia de anemia infecciosa equina en los tres biomas presentes en el estado de Mato Grosso (Amazonia, Cerrado y Pantanal). Entre septiembre y diciembre de 2014 se extrajeron muestras a 3.858 equinos de 1.067 rebaños, a las que se aplicó la técnica de inmunodifusión en gel de agar para detectar anticuerpos contra el virus de la anemia infecciosa equina: todo rebaño en el que hubiera un animal seropositivo era considerado un foco. La tasa de prevalencia de rebaños infectados resultó del 17,2% (intervalo de confianza [IC] al 95%: 14,9­19,8) y la de individuos infectados del 6,6% (IC 95%: 5,8­7,5). Las tasas más elevadas se observaron en la región de Pantanal: un 36,1% (IC 95%: 30,8­41,7) de prevalencia de rebaño y un 17,0% (IC 95%: 14,7­19,6) de prevalencia individual. La distribución espacial del riesgo relativo se determinó con arreglo a la densidad kernel, proceso que reveló la presencia de tres grandes conglomerados: las mayores tasas de prevalencia se situaban en las regiones del noroeste (en el caso del bioma amazónico), el noreste (biomade Cerrado) y el sur (bioma de Pantanal). Se observó que existía una estrecha correlación espacial entre explotaciones, y aunque en los biomas de la Amazonia y Cerrado había elevadas tasas de prevalencia intrarrebaño, fue en el bioma de Pantanal donde se observó la correlación espacial más estrecha con los focos de anemia infecciosa equina. La presencia de equinos seropositivos venía asociada a variables relacionadas con la gestión de las explotaciones, hecho que pone de relieve la influencia humana en la cuestión. A tenor de los resultados, cabe concluir que la anemia infecciosa equina está presente en todos los biomas del estado y que los factores de riesgo guardan relación con la interferencia humana en el proceso de transmisión. Ante tal situación, convendría evaluar de nuevo el programa de lucha contra la anemia infecciosa y poner mayor acento en las medidas profilácticas para combatir la enfermedad.

An electrospray ionization mass spectrometry study of azidoacetic acid/transition metal complexes.

RATIONALE: The complexation behavior of transition metals with organic azides by electrospray ionization (ESI) tandem mass spectrometry (MS/MS) is not completely understood. In this study, fragmentation patterns of complex ions having azidoacetic acid coordinated to Ni/Co/Fe were elucidated. The role of transition metals in the mediation of ligand rearrangements in gas phase is experimentally supported. METHODS: The complexation of some transition metals, nickel, cobalt and iron, by azidoacetic acid was studied by means of ESI and MS/MS. Fragmentation patterns were discerned via consecutive MS/MS experiments on an ion trap mass spectrometer and confirmed by high-resolution (HR) Fourier transform ion cyclotron resonance MS. Density functional theory (DFT) calculations were used to characterize the major ions observed in MS. RESULTS: Only singly positively charged complex ions were detected presenting various stoichiometries. MS/MS and theoretical calculations allowed us to confirm assignments and coordination sites. Structural evidence suggested that the azidoacetic acid can behave as monodentate and/or bidentate and coordination through the oxygen and nitrogen atoms are both possible. Experimental evidence strongly points to a role of Ni/Co/Fe, in oxidative state (I), in mediating C-C bond activation in the gas phase. CONCLUSIONS: MS/MS and HRMS experiments were able to elucidate azidoacetic acid complexation with Ni/Co/Fe and several gas-phase processes involving metal reduction and rearrangements. The definition of the coordination pattern dictated by the competition between the nitrogen and the oxygen atoms is also dependent on the metal centre in a very dynamic process. Copyright © 2017 John Wiley & Sons, Ltd.

Multi-effect of the water-soluble Moringa oleifera lectin against Serratia marcescens and Bacillus sp.: antibacterial, antibiofilm and anti-adhesive properties.

AIMS: To evaluate the antibiofilm potential of water-soluble Moringa oleifera seed lectin (WSMoL) on Serratia marcescens and Bacillus sp. METHODS AND RESULTS: WSMoL inhibited biofilm formation by S. marcescens at concentrations lower than 2·6 µg ml-1 and impaired bacterial growth at higher concentrations, avoiding biofilm formation. For Bacillus sp., the lectin inhibited bacterial growth at all concentrations. The antibiofilm action of WSMoL is associated with damage to bacterial cells. WSMoL did not disrupt preformed S. marcescens biofilms but was able to damage cells inside them. On the other hand, the lectin reduced the number of cells in Bacillus sp. biofilm treated with it. WSMoL was able to control biofilm formation when immobilized on glass surface (116 µg cm-2 ), damaging S. marcescens cells and avoiding adherence of Bacillus sp. cells on glass. The Bacillus sp. isolate is member of Bacillus subtilis species complex and closely related to species of the conspecific 'amyloliquefaciens' group. CONCLUSION: WSMoL prevented biofilm development by S. marcescens and Bacillus sp. and the antibiofilm effect is also observed when the lectin is immobilized on glass. SIGNIFICANCE AND IMPACT OF THE STUDY: Taking together, our results provide support to the potential use of WSMoL for controlling biofilm formation by bacteria.

Short communication: Passive shedding of Mycobacterium avium ssp. paratuberculosis in commercial dairy goats in Brazil.

Goat farming is a low-cost alternative to dairy production in developing countries. In Brazil, goat production has increased in recent years due in part to the implementation of programs encouraging this activity. Mycobacterium avium ssp. paratuberculosis (MAP) is the causative agent of paratuberculosis, a disease that causes chronic granulomatous enteritis in ruminants, but MAP transmission dynamics are still poorly understood in goats. In a previously published study of our research group, 10 dairy goat farms (467 animals) from Minas Gerais state were analyzed for MAP detection; 2 fecal cultures and 11 milk samples tested positive for MAP by conventional PCR and were confirmed by sequencing. Because no clinical signs were observed over 1 yr of monitoring, we hypothesized that these MAP-positive goats could be passive shedders. Thus, in the present study, 4 positive goats (4/13) from the previous study were purchased and feces and milk samples were collected for evaluation (twice, with an interval of 3 mo between tests) by culture of MAP, IS900 PCR, or both. All analyses were negative for MAP. At the last time point, blood samples were collected for ELISA, the animals were killed, and tissues collected for tissue culture and histopathology. At necropsy, no macroscopic lesions related to paratuberculosis were observed. Similarly, no histological changes were observed and MAP in samples stained by Ziehl-Neelsen was not detected. These animals were characterized as potential passive shedders with upward contamination of the teat canal by MAP. This is the first report of the passive shedding phenomenon in goats in Brazil and it highlights the importance of identifying these animals for control programs and to ensure the quality of dairy products.

A feed-forward loop between SroC and MgrR small RNAs modulates the expression of eptB and the susceptibility to polymyxin B in Salmonella Typhimurium.

Base-pairing small RNAs (sRNAs) regulate gene expression commonly by direct interaction with cognate mRNAs. Nevertheless, recent studies have expanded this knowledge with the discovery of the RNA 'sponges' which are able to interact and repress the functions of classical base-pairing sRNAs. In this work, we present evidence indicating that the sponge RNA SroC from Salmonella enterica serovar Typhimurium base pairs with the MgrR sRNA, thereby antagonizing its regulatory effects on both gene expression and resistance to the antimicrobial peptide polymyxin B (PMB). By a predictive algorithm, we determined putative SroC-MgrR base-pairing regions flanking the interaction area between MgrR and its target mRNA, eptB, encoding a LPS-modifying enzyme. With a two-plasmid system and compensatory mutations, we confirmed that SroC directly interacts and down-regulates the levels of MgrR, thus relieving the MgrR-mediated repression of eptB mRNA. Since it was previously shown that an Escherichia coli strain carrying an mgrR deletion is more resistant to PMB, we assessed the significance of SroC in the susceptibility of S. Typhimurium to PMB. Whereas the sroC deletion increased the sensitivity to PMB, as compared to the wild-type, the resistance phenotypes between the ΔmgrR and ΔsroCΔmgrR strains were comparable, evidencing that mgrR mutation is epistatic to the sroC mutation. Together, these results indicate that both SroC and MgrR sRNAs compose a coherent feed-forward loop controlling the eptB expression and hence the LPS modification in S. Typhimurium.

Barriers associated with frequency of leisure-time physical activity among Brazilian adults of different income strata.

This study aimed to estimate the prevalence of the main perceived barriers to leisure-time physical activity (LTPA) and their associations with the frequency of LTPA in a representative sample of industrial workers from Brazil (n = 47,477), according to their income strata (low income: ≤$US280, middle income: $US281-$US1400, and high income: ≥$US1401). Data were collected between 2006 and 2008 via questionnaires about the main perceived barrier to LTPA and the frequency of LTPA. Multinomial logistic regression was performed to evaluate differences among groups. There was a lower prevalence of regular practice of LTPA in the low- (15.8%) and middle-income strata (18.2%) than among the individuals of the high-income stratum (27.6%). A large proportion of workers who regularly participated in LTPA reported no barriers (low: 43.1%; middle: 46.8%; high: 51.6%). Additional obligations and fatigue were the two most common perceived barriers in all family income strata among participants who engaged in different frequencies of LTPA. The odds for all perceived barriers showed a positive trend related to frequency of LTPA (from regular to no LTPA), with higher values according to income. In summary, the ordering of the main perceived barriers to LTPA differed according to workers' income stratum and frequency of engaging in LTPA.

DNA barcoding reveals high levels of genetic diversity in the fishes of the Itapecuru Basin in Maranhão, Brazil.

DNA barcoding is a useful complementary tool for use in traditional taxonomic studies due to its ability to detect cryptic species, and may be particularly efficient in the identification of fish species. The fish fauna of the Itapecuru River represents an important fishery resource in the Brazilian State of Maranhão, although it is currently suffering increasing degradation as a result of anthropogenic impacts. Therefore, DNA barcoding was used in the present study to identify fish species and establish a database of the rich freshwater fish fauna of Maranhão. A total of 440 specimens were analyzed, corresponding to 64 species belonging to 59 genera, 31 families, and 10 orders. Overall, 92.19% of these species could be identified by DNA barcoding, and were characterized by low levels (average 0.80%) of intra-specific divergence. However, five species (Anableps anableps, Gymnotus carapo, Sciades couma, Pseudauchenipterus nodosus, and Leporinus piau) presented values of mean genetic divergence above 3%, indicating the existence of cryptic diversity in these fishes. The DNA barcoding approach permitted the analysis of a large number of specimens and facilitated the discrimination and identification of closely related fish species in the Itapecuru Basin.

Doxorubicin-loaded galactose-conjugated poly(d,l-lactide-co-glycolide) nanoparticles as hepatocyte-targeting drug carrier.

The objective of this work is to produce doxorubicin-loaded galactose-conjugated poly(d,l-lactide-co-glycolide) (PLGA) nanoparticles (NPs) to be specifically recognised by human hepatoma cellular carcinoma (Hep G2) cells and assess NPs cytotoxicity. Doxorubicin-unloaded and doxorubicin-loaded galactose-conjugated PLGA NPs were prepared using an emulsion method and characterised for morphology, size, drug release behaviour, Hep G2 recognition and cell cytotoxicity. The produced doxorubicin-loaded PLGA-galactose-conjugate nanoparticles (PLGA-GAL NPs) are spherical in shape with a size of 365 ± 74 nm, a drug encapsulation efficiency of 69% and released in a biphasic pattern with higher release rates at pH 5. In vitro cell studies confirmed the specific interaction between the receptors of Hep G2 and the PLGA-GAL NPs. Cell cytotoxicity tests showed that unloaded NPs are non-toxic and that doxorubicin-loaded NPs caused a cellular viability decrease of around 80%, therefore representing a promising approach to improve liver-specific drug delivery.