Environmentally friendly concrete block production: valorization of civil construction and chemical industry waste

In the present work, a study was carried out on the dosage of wastes from the chemical industry (tannery sludge) and civil construction (concrete and plaster) in mixtures used in concrete blocks' production. The objective was the application of these blocks in paving. The characterization of the materials used was performed employing X-ray diffractometry (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS). The effect of the different residues on the blocks' properties was evaluated through compressive strength, flexion-traction, water absorption, abrasion resistance, and leaching tests. The results indicated that the concrete paving blocks produced with the addition of residues did not obtain gains in the values of mechanical resistance to compression and traction in bending compared to blocks made with standard raw material. However, the blocks produced with construction waste presented satisfactory results for application in street paving after 7 days of concrete curing, reaching values between 36.54 and 44.6 MPa for the mentioned properties. These values also increased to 21.4% within 28 days of curing. The blocks produced with plaster showed values between 37.03 and 39.85 MPa after 28 days of curing, allowing their use for street paving. On the other hand, the blocks containing residues from the chemical industry had lower strengths, reaching a maximum of 29.36 MPa after 28 days of curing. In addition, it was also noted that the blocks produced with recycled concrete showed an improvement in performance for a composition of 50% recycled material.

Regional support in the health regions of Rio de Janeiro state: a strategy for strengthening SUS

Brazil is one of the few countries in the world with more than 200 million inhabitants that has a universal public health system. In its 30 years of existence, the Unified Health System (SUS) has brought many advances to the Brazilian society. However, it still faces challenges to ensure health services in quantity and quality to the entire population. Federal, state and municipal government levels share the responsibility for its management and financing. In this governance scheme, it is the Municipal Health Secretariats (MHS) of the 5,596 Brazilian municipalities that are primarily responsible for providing and managing health services. Given the importance of this responsibility, Councils of Municipal Health Departments (COSEMS) and the National Council of Municipal Health Departments (CONASEMS) were created in 1986. Their role is to promote the articulation and negotiation of their interests with the federal and state levels. In Rio de Janeiro, a team of specialized professionals has been providing support for COSEMS-RJ since 2012. The team carries out activities in the nine regions of the state, which has 92 municipalities and more than 16 million inhabitants, the 3rd largest population in Brazil. Its activities are maintained by CONASEMS, the Ministry of Health and the State University of Rio de Janeiro (UERJ). The objetive of this report is to present the experience of the expert team of COSEMS RJ as a strategy for strengthening regional governance and intergovernmental relations. Providing specialized technical support for MHS has improved local management of SUS and has allowed for the establishment of regionalized health care networks in Rio de Janeiro.

Key messages

The project improves the participation of municipal managers and teams in regional spaces. It strengthens their capacity for intergovernamental decision-making and regionalization of the health system. The project qualifies the municipal management for fundraising, knowledge building, policy implementing and monitoring, as well as participatory planning.

Intraspecies Variability Affects Heterotypic Biofilms of Porphyromonas gingivalis and Prevotella intermedia: Evidences of Strain-Dependence Biofilm Modulation by Physical Contact and by Released Soluble Factors

It is well known that strain and virulence diversity exist within the population structure of Porphyromonas gingivalis. In the present study we investigate intra- and inter-species variability in biofilm formation of Porphyromonas gingivalis and partners Prevotella intermedia and Prevotella nigrescens. All strains tested showed similar hydrophobicity, except for P. gingivalis W83 which has roughly half of the hydrophobicity of P. gingivalis ATCC33277. An intraspecies variability in coaggregation of P. gingivalis with P. intermedia was also found. The association P. gingivalis W83/P. intermedia 17 produced the thickest biofilm and strain 17 was prevalent. In a two-compartment system P. gingivalis W83 stimulates an increase in biomass of strain 17 and the latter did not stimulate the growth of P. gingivalis W83. In addition, P. gingivalis W83 also stimulates the growth of P. intermedia ATCC25611 although strain W83 was prevalent in the association with P. intermedia ATCC25611. P. gingivalis ATCC33277 was prevalent in both associations with P. intermedia and both strains of P. intermedia stimulate the growth of P. gingivalis ATCC33277. FISH images also showed variability in biofilm structure. Thus, the outcome of the association P. gingivalis/P. intermedia seems to be strain-dependent, and both soluble factors and physical contact are relevant. The association P. gingivalis-P. nigrescens ATCC33563 produced larger biomass than each monotypic biofilm, and P. gingivalis was favored in consortia, while no differences were found in the two-compartment system. Therefore, in consortia P. gingivalis-P. nigrescens physical contact seems to favor P. gingivalis growth. The intraspecies variability found in our study suggests strain-dependence in ability of microorganisms to recognize molecules in other bacteria which may further elucidate the dysbiosis event during periodontitis development giving additional explanation for periodontal bacteria, such as P. gingivalis and P. intermedia, among others, to persist and establish chronic infections in the host.

Sucrose substitutes affect the cariogenic potential of Streptococcus mutans biofilms

Streptococcus mutans is considered the primary etiologic agent of dental caries and contributes significantly to the virulence of dental plaque, especially in the presence of sucrose. To avoid the role of sucrose on the virulence factors of S. mutans, sugar substitutes are commonly consumed because they lead to lower or no production of acids and interfere with biofilm formation. This study aimed to investigate the contribution of sugar substitutes in the cariogenic potential of S. mutans biofilms. Thus, in the presence of sucrose, glucose, sucralose and sorbitol, the biofilm mass was quantified up to 96 h, the pH of the spent culture media was measured, the expression of biofilm-related genes was determined, and demineralization challenge experiments were conduct in enamel fragments. The presence of sugars or sugar substitutes profoundly affected the expression of spaP, gtfB, gtfC, gbpB, ftf, vicR and vicX in either biofilm or planktonic cells. The substitution of sucrose induced a down-regulation of most genes involved in sucrose-dependent colonization in biofilm cells. When the ratio between the expression of biofilm and planktonic cells was considered, most of those genes were down-regulated in biofilm cells in the presence of sugars and up-regulated in the presence of sugar substitutes. However, sucralose but not sorbitol fulfilled the purpose of reducing the cariogenic potential of the diet since it induced the biofilm formation with the lowest biomass, did not change the pH of the medium and led to the lowest lesion depth in the cariogenic challenge.

Food expenditures, cariogenic dietary practices and childhood dental caries in southern Brazil

Family expenditures on food for children may represent an important barrier to the adoption of healthy feeding practices in populations of low socioeconomic status. The aim of this study was to explore the relationship between cariogenic feeding practices, expenditures on food for children and dental caries. This cross-sectional study included 329 four-year-old children from São Leopoldo in southern Brazil. Cariogenic dietary practices were assessed at 4 years of age using two 24-hour recalls conducted with the children's mothers. Expenditures on food for children were estimated based on all reported food items and the respective amounts ingested. Early childhood caries and severe early childhood caries were assessed by clinical examination at 4 years of age. Cariogenic dietary habits were not associated with lower food expenditures. On the contrary, in multivariable regression analysis, the intake of chocolate (p = 0.007), soft drinks (p = 0.027) and a higher number of meals and snacks per day (p < 0.001) was associated with greater expenditures on food for children. No statistically significant differences were observed in food expenditures or in the proportion of household income spent on feeding children between caries-free children, those with early childhood caries and those with severe early childhood caries. In conclusion, keeping children free of dental caries does not necessarily increase food expenditures or the proportion of household income spent on feeding children in low-socioeconomic status populations. Some cariogenic dietary practices were associated with greater expenditures on child feeding.

Invasion of human coronary artery endothelial cells by Streptococcus mutans OMZ175

INTRODUCTION

Dissemination of oral bacteria into the bloodstream has been associated with eating, oral hygiene, and dental procedures; including tooth extraction, endodontic treatment, and periodontal surgery. Recently, studies identified Streptococcus mutans, the primary etiological agent of dental caries, as the most prevalent bacterial species found in clinical samples from patients who underwent heart valve and atheromatous plaque surgery.

METHODS

By using antibiotic protection assays, we tested the capacity of 14 strains of S. mutans to invade primary human coronary artery endothelial cells (HCAEC).

RESULTS

Serotype e strain B14 and serotype f strain OMZ175 of S. mutans were able to efficiently invade HCAEC. Among the tested strains, serotype f S. mutans OMZ175 was the most invasive, whereas strains of serotype c S. mutans, the most prevalent serotype in dental plaque, were not invasive. Based on its high invasion rate, we further investigated the invasive properties of serotype f OMZ175. Using transmission electron microscopy and antibiotic protection assays we demonstrate that S. mutans OMZ175 is capable of attaching to the HCAEC surface, entering the cells and surviving in HCAEC for at least 29 h.

DISCUSSION

Our findings highlight a potential role for S. mutans in the pathogenesis of certain cardiovascular diseases.

Porphyromonas gingivalis and the autophagic pathway: an innate immune interaction?

Autophagy is a mechanism used to maintain several intracellular functions essential to eukaryotic cells. Recently, a role for autophagy in innate and adaptive immunity has also been established including the elimination of invading bacteria. Although some intracellular pathogens are killed by autophagy, several others subvert autophagy to the pathogen's benefit for survival and replication. Porphyromonas gingivalis, an important periodontal pathogen, has been shown to stimulate autophagy in endothelial cells and to use the autophagic pathway to its advantage. In human coronary artery endothelial cells (HCAEC), P. gingivalis localizes within autophagosomes. After intracellular uptake, P. gingivalis transits from early autophagosomes to late autophagosomes and prevents the formation of autolysosomes, either by delaying the autophagosome-lysosome fusion or by redirecting the normal autophagic trafficking. In addition, P. gingivalis was also found to stimulate autophagy in human aortic endothelial cells (HAEC) since co-localization of LC3-II, an autophagosome marker, with P. gingivalis was observed. The trafficking of P. gingivalis into the autophagic pathway appears to be dependent upon the host cell type. Survival of P. gingivalis through the subversion of the host autophagic pathway can be considered a bacterial strategy to evade the innate immune system and persist in the host.

Trabalho imaterial e sofrimento psíquico: o pós-fordismo no jornalismo industrial

Este artigo reflete criticamente sobre implicações da recente fase do modo de produção capitalista nas rotinas de produção num jornal do Rio Grande do Sul. Trata-se de um estudo de caso cuja coleta de dados se deu através de investigação bibliográfica, seis entrevistas semi-estruturadas com jornalistas e observação não-participante. Como exercício teórico, é abordada a passagem da etapa fordista do capital para o pós-fordismo, enfatizando o conceito de compressão do tempo. Posteriormente, são analisados o deadline do periódico e as mudanças na atividade jornalística. Aqui, é traçada uma inter-relação entre as atuais rotinas de produção do jornalismo industrial e a emergência do trabalho imaterial na etapa recente do capital. Finalmente, através de estudos da subjetividade no trabalho, são analisadas as reações dos próprios jornalistas às transformações na organização do trabalho dentro da redação.

Susceptibility of Prevotella intermedia/Prevotella nigrescens (and Porphyromonas gingivalis) to propolis (bee glue) and other antimicrobial agents

Black-pigmented gram-negative anaerobes such as Porphyromonas gingivalis and Prevotella intermedia are suspected pathogens in adult periodontitis, whereas Prevotella nigrescens has been associated with health. Antimicrobial resistance among bacteria from this group has been reported in the past decade. This research aimed to evaluate and compare the susceptibility profile of 17 P. intermedia/P. nigrescens isolates recovered from patients with periodontitis and three reference strains to six antimicrobials, prescribed in dentistry in Brazil, and propolis (bee glue). The antimicrobial agents tested were tetracycline, penicillin, clindamycin, erythromycin, metronidazole, meropenem and six ethanolic extracts of propolis (EEPs) from Brazil. The reference strains P. gingivalis ATCC 33277 and P. intermedia ATCC 25611 were used for determination of minimum bactericidal concentration (MBC) and for time-kill assay to the EEPs. All of the strains were susceptible to penicillin, erythromycin, meropenem, metronidazole and 95% of them (n=19) to tetracycline. Thirty six percent (n=7) of the P. intermedia/P. nigrescens strains tested were resistant to clindamycin. As for propolis activity, all strains were susceptible and the minimum inhibitory concentration values ranged from 64 to 256 microg/mL. For the reference strains P. gingivalis ATCC 33277 and Prevotella intermedia ATCC 25611 the MBC was 256 microg/mL and death was observed within 3 h of incubation for P. gingivalis and within 6 h for P. intermedia. The action of propolis (bee glue) against suspected periodontal pathogens suggests that it may be of clinical value.

Hemolytic activity of Prevotella intermedia and Prevotella nigrescens strains: influence of abiotic factors in solid and liquid assays

The influence of growth medium, hemin and menadione, blood source and atmosphere of incubation on the expression of hemolytic activity of 25 strains of Prevotella intermedia and Prevotella nigrescens was evaluated. The best hemolytic activity was observed for samples of both species growing in brain heart infusion agar and incubated in Brewer-like anaerobic jars for 48 h. Hemolysis was less intense and occurred later in the presence of hemin and menadione in solid media. beta-Hemolysis was detected for medium supplemented with horse or human blood and alpha-hemolysis was observed when sheep blood was used. These results suggesting some specificity for the hemolytic activity were also observed in liquid assays in which sheep erythrocytes were found to be resistant to hemolysis while horse and human cells where lysed. In liquid assays, the hemolytic activity of all studied strains remained stable in the pH range of 6.0 to 8.5 and was not altered by iron-scavenging compounds or atmosphere of incubation. The phenomenon of hot/cold hemolysis was ruled out as the mechanism of action of P. intermedia and P. nigrescens hemolysin.

Plasma ascorbate concentrations are not correlated with milk somatic cell count and metabolic profile in lactating and dry cows

The purpose of this study was to determine the effects of stage and the number of lactation on plasma ascorbate concentration and to establish the association between plasma ascorbate concentrations and plasma glucose, insulin, nonesterified fatty acids (NEFA), beta-hydroxybutyrate (BHBA), aspartate aminotransferase (AST), milk somatic cell count (SCC), milk yield, and body condition score (BCS) in dairy cows. Holstein cows (n = 193) from three different herds were used in this study. Animals were randomly selected, and assigned to five groups according to stage of lactation (group 1, dry cows; group 2, 1 to 28 d; group 3, 29 to 56 d; group 4, 57 to 140 d; group 5, 141 to 280 d), and the number of lactation (primiparous or multiparous). Plasma ascorbate concentration, plasma glucose concentration, serum insulin concentration, plasma NEFA concentration, plasma BHBA concentration, serum AST concentration, milk SCC, milk yield, and BCS were measured. The results of this study demonstrate that plasma ascorbate concentrations do not change in response to stage of lactation, or number of lactations. Among the several variables studied, none was found that, singly or in combinations, could explain variations in ascorbic acid concentrations.