Medicina regenerativa de cartílago: efecto del tratamiento con ácido hialurónico reticulado bifásico en lesiones osteocondrales / Regenerative medicine: effect of treatment with biphasic cross-linked hyaluronic acid in osteochondral lesions

Objetivo: Evaluar si el tratamiento con ácido hialurónico reticulado bifásico de lesiones osteocondrales promovería la regeneración del tejido cartilaginoso, favoreciendo así la reparación de la lesión. Materiales y métodos: Quince conejos hembra adultos fueron divididos aleatoriamente en tres grupos: grupo 1, de control; grupo 2 y grupo 3, sometidos a una estrategia quirúrgica de lesión osteocondral en la rodilla derecha (4 mm de diámetro, 5 mm de profundidad), el grupo 3 recibió tratamiento con 0,2 ml de ácido hialurónico por vía intrarticular después de la cirugía. Se realizaron controles clínicos, bioquímicos, histopatológicos y estudios por imágenes. Resultados: Se detectaron menos casos de dolor a la palpación en el grupo 3 que en el grupo 2 a partir de los 45 días. En la resonancia magnética, casi todas las muestras del grupo 3 tenían signos de regeneración del tejido cartilaginoso en el sitio de la lesión, sin edema óseo, ni derrame articular significativo. Los estudios histopatológicos de las muestras del grupo 3 indicaron un aumento de la matriz extracelular propia de tejido cartilaginoso, comparada con la del grupo 2, con hipercelularidad, dada por condrocitos, los que formaban grupos isogénicos axiales y coronales. Conclusiones: Este estudio brinda evidencias de que el tratamiento con ácido hialurónico reticulado bifásico en unidades experimentales de conejos con lesión osteocondral no tuvieron dolor en etapas tempranas después de la lesión, a diferencia de las unidades intervenidas y sin dicho tratamiento. A su vez, los estudios por imágenes e histopatológico mostraron la reparación del tejido dañado.

Objective: To demonstrate whether treatment with biphasic cross-linked hyaluronic acid in osteochondral lesions promotes the regeneration of cartilage tissue. Materials and methods: Fifteen adult female rabbits were randomly assigned to three groups. G1 was the control group, whereas G2 and G3 underwent surgery to treat an osteochondral injury in the right knee (4mm diameter, 5mm depth). G3 received treatment with 0.2 ml of hyaluronic acid intrarticularly after surgery. Clinical, biochemical, histopathological controls and imaging studies were performed. Results:Clinically, G3 exhibited less pain on palpation than G2 after 45 days. In G3, almost all samples showed evidence of cartilage tissue regeneration at the injury site, with neither bone edema or considerable joint effusion detected on MRI. The histological tests of G3 samples revealed an increase in the extracellular matrix of cartilaginous tissue when compared to G2, with hypercellularity caused by chondrocytes that formed axial and coronal isogenic groups. Conclusions: This study provides evidence that treatment with biphasic cross-linked hyaluronic acid in experimental units of rabbits with osteochondral injuries did not cause pain in the early stages of the injury. In turn, imaging and histopathological studies revealed that the injured tissue had been repaired.

Removal of cephalexin and erythromycin antibiotics, and their resistance genes, by microalgae-bacteria consortium from wastewater treatment plant secondary effluents.

Antibiotics have become a concern in the aquatic environments owing to the potential development of bacterial resistances. Thus, this study evaluated the removal of cephalexin (CEP) and erythromycin (ERY) from a local wastewater treatment plant (WWTP) effluent, mediated by microalgae-bacteria consortium. Likewise, the removal of correlated antibiotics resistance genes blaTEM and ermB was also assessed. The incubation results showed that the added concentrations of selected antibiotics did not restrain the consortium growth. Moreover, CEP and ERY were almost completely removed after the cultivation period, reaching total removals of 96.54% and 92.38%, respectively. The symbiotic interaction between microalgae and bacteria plays a role in the kinetics removal of CEP and ERY. The abundance of blaTEM and ermB was reduced by 0.56 and 1.75 logs, respectively. Lastly, our results suggest that technology based on natural microalgae-bacteria consortium could be a potential alternative to improve the quality of WWTP effluents.

Hydraulic and auto-depurative characteristics of the Gualaxo do Norte River after the Fundão dam rupture.

The hydraulic characteristics of the Gualaxo do Norte River (RGN), a tributary of the upper Rio Doce basin, were affected in November 2015 by the rupture of the iron ore tailings dam at Fundão, in Bento Rodrigues, Mariana, Minas Gerais. We analyzed two sections of the RGN, located upstream and downstream of the Fundão dam. Measurements were taken at 11 stations along the main river in distinct seasonal periods, including river depth, river width, velocity, and flow. We also calculated the deoxygenation coefficient (K1) and the reaeration coefficient (K2) and collected elaborate bathymetric profiles of the sections. Anthropogenic interference influenced the river's hydraulic characteristics mainly in relation to the depth. In upstream sections, the changes are believed to be due to mining activities at the head of the river, while downstream effects were due to the introduction of iron ore tailings coming from the rupture of the Fundão dam. Despite these influences, deoxygenation coefficient values were typical for clean water, and the reaeration coefficient findings show that the RGN is efficient at biological degradation of the organic matter even receiving untreated domestic sewage from riparian communities. With the results obtained in this work, we seek to replicate a source of information about the current state of the region and to contribute information to future river planning, control, and restoration projects.

Antibiotic consumption in developing countries defies global commitments: an overview on Brazilian growth in consumption.

Faster spread of epidemics has turned local concerns into global crises; antimicrobial resistance (AMR) is being considered a major threat to public health in the twenty-first century. Antibiotic misuse plays a great role in accelerated AMR; thus, understanding and discussing consumption patterns has been a trend topic over the past years. Developing countries, such as Brazil, have high growth rates in antibiotic consumption, potentially impacting global environmental safety. This study presents the compiled information from the Brazilian Health Regulatory Agency (ANVISA) on antibiotic dispensation across the country and maps the consumption trends between the years of 2013 and 2016. The most consumed substances were beta-lactams (amoxicillin and cephalexin) and macrolides (azithromycin). National relative growth consumption in the mentioned period was 18%. At the local level, growth of consumption ranged from 4 to 85%, with rampage growth concentrated in the North and Northeast regions. Brazilian laws, such as restriction of over-the-counter sales and mandatory report on dispensation, seem to have little effect on the national antibiotic consumption growth. This phenomenon growth is still elevated if compared with developed countries, demonstrating the need for further surveillance as well as coordinated efforts aiming at antibiotic use and AMR prevention.

Geochemical evaluation of bottom sediments affected by historic mining and the rupture of the Fundão dam, Brazil.

The rupture of the Fundão dam released about 39 million m3 of tailings into the Rio Doce/Brazil. The sediment load increase in the affected rivers has become a concern. As such, this article provides recent information about the region. In addition, based on past studies in the region, it shows the magnitude and dynamics of the environmental impacts caused by the rupture of the dam on the bottom sediments. Sediment samples in different seasonal periods were collected at eleven sampling stations located along the Gualaxo do Norte River, the first tributary of the Rio Doce affected by the environmental disaster. These sediments underwent physical, chemical, and granulometric analyses for their organic, metal, and semimetal content. The contamination factor and the enrichment factor of the samples also were calculated. To evaluate the anthropogenic contributions to sediment metal concentrations, reference values (regional background values) for the Gualaxo do Norte River were used. The results indicate that, in the sampling stations not affected by the disaster, the concentrations of the metals and semimetals reflect the geology of the Quadrilátero Ferrífero. However, in the area affected by the environmental disaster, there were changes in the chemical and physical properties of the bottom sediment, mainly in the concentrations of iron, organic matter, and fine sediment fractions. This was reflected in the contamination factors and enrichment factors calculated for the sediments of the sampling stations. Iron and manganese concentrations in sediments are much higher than other rivers in the world that are unaffected by mining activities. The observed changes in the bottom sediments of the river suggest a need for constant monitoring of the iron because the iron oxide minerals present in silt and clay have a high adsorption capacity. In the long term, these factors may contribute to the decrease of the quality of these sediments and consequently of the waters and biota present in these environments.

Influence of environmental and anthropogenic factors at the bottom sediments in a Doce River tributary in Brazil.

In developing countries, it is uncommon to find watersheds that have been the object of detailed environmental studies. It makes the assessment of the magnitude of environmental impacts and pollution of these sites difficult. This research demonstrated ways to understand the dynamics of river bottom sediments contamination, even for watersheds with a lack of environmental data. Based on geochemical affinity, we conducted a comprehensive study on the concentration of metals and metalloids. Then, we discussed the probable origin of the concentration of these elements at the bottom sediment along the Matipó River. The Matipó River is an important tributary of the Doce River, which stood out in international headlines because of the mining tailing dam disaster in Mariana, Minas Gerais, in 2015. The bottom sediment samples were taken in 25 stations located along the basin in different seasonal periods. The results showed that copper ([Formula: see text] = 464.7 mg kg-1) and zinc ([Formula: see text] = 287.7 mg kg-1) probably have natural origin, despite of the high concentrations. Lead ([Formula: see text] = 28.0 mg kg-1), chromium ([Formula: see text] = 153.2 mg kg-1), and nickel ([Formula: see text] = 41.8 mg kg-1) also had high concentrations at some collecting stations, and this probably reflected the local natural conditions. The bedrock of the studying basin is dominantly composed of metabasalts and metatonalites interlayered with calcitic and dolomitic metalimestone. On the other hand, the concentration was worrisome in stations near human activities, possibly due to impacts caused by unsustainably agriculture and livestock.