One-year variation in quantity and properties of microplastics in mussels (Mytilus galloprovincialis) and cockles (Cerastoderma edule) from Aveiro lagoon.

As filter feeders, marine bivalves inhabiting estuarine and coastal areas are directly exposed to microplastics (MPs) in water. To assess whether MPs number, and their shape, size, colour, and polymer type present in mussels (Mytilus galloprovincialis) and cockles (Cerastoderma edule) varied over one year, bivalves were collected over the year of 2019 in the lower part of the coastal Aveiro lagoon, Portugal. After extraction from the bivalve's whole-body soft tissues, a subset of the visually inspected particles was randomly separated for identification using the Fourier-transform mid-infrared (FT-MIR) spectroscopy. A fraction of the inspected particles, 26-32% of particles >100 µm, and 59-100% of smaller ones were confirmed as MPs. Concentrations varied within the intervals of 0.77-4.3 items g-1 in mussels and 0.83-5.1 items g-1 in cockles, with the lowest values observed in January. In winter, the accumulation of large-sized fibers was composed of a mixture of plastic types, which contrasted against the most abundant MPs in summer consisting mainly of polyethylene of diverse size classes and shapes. Temperature decrease registered in winter might have triggered a lower filtration rate, resulting in lower MPs concentrations in the whole-soft body tissues of organisms. Different properties of MPs found in bivalves between January-February and August-September appear to reflect changes in the characteristics of MPs available in the Aveiro lagoon.

Alterações hematológicas provocadas pelo ultra-som de 1MHz na forma contínua aplicadas no tratamento da fase aguda de lesão muscular iatrogênica em ratos / Hematological changes produced by 1MHz continuous ultrasound, applied during the acute phase of iatrogenic muscle injury in rats

CONTEXTUALIZAÇÃO: A literatura demonstra o efeito benéfico da terapia ultra-sônica de baixa intensidade sobre o processo de cicatrização de vários tecidos. OBJETIVO: Avaliar o efeito do ultra-som contínuo (USC) sobre a dinâmica hematológica do processo inflamatório agudo de lesão muscular iatrogênica. MÉTODOS: Foram utilizados 16 ratos da raça Wistar (350 a 400g), divididos em grupo controle (GC=8) e grupo experimental (G1=8), submetidos à incisão cirúrgica na face lateral do membro posterior direito, onde o músculo bíceps femoral foi lesionado transversalmente. O USC (1MHz) foi aplicado sobre o local da lesão a uma intensidade de 0,4W/cm², durante três minutos, na 1ª, 8ª e 24ª hora após a lesão. Nestes períodos, foram realizadas as coletas de sangue por punção venosa do plexo retroorbital para as análises sangüíneas das séries brancas e vermelhas. RESULTADOS: O USC diminui 8 por cento dos eritrócitos na primeira coleta (9,9±0,1 versus 7,8±0,1; x10(5)/mm³, p<0,001); dobrou os neutrófilos segmentados na segunda coleta (3.166,8±161,4 versus 6.426,2±306,0; x10³/mm³ p=0,008) e os eosinófilos na terceira coleta (2.883,6±99,0 versus 4.714,4±275,2; x10³/mm³ p=0,011) em relação ao GC. Não se observaram diferenças entre os grupos no hematócrito, leucócitos totais, neutrófilos bastonetes, monócitos e linfócitos, nos três momentos estudados. CONCLUSÕES: A aplicação do USC no tratamento agudo de lesão muscular é contra-indicada nesta condição, pois promove a redução dos eritrócitos, aumento dos neutrófilos segmentados e dos eosinófilos, favorecendo a hemorragia e o aumento do processo inflamatório.

BACKGROUND: The literature shows the beneficial effects of low-intensity ultrasound therapy on the healing process of several biological tissues. OBJECTIVE: To evaluate the effects of continuous ultrasound (CUS) on the hematological dynamics of an acute inflammatory process in iatrogenic muscle injuries. METHODS: Sixteen Wistar rats (350 to 400g) were divided into a control group (CG=8) and an experimental group (G1=8). The rats were submitted to a surgical incision on the lateral aspect of the right hind limb, in which the biceps femoris muscle was transversally injured. The CUS (1MHz) was applied to the injury site at an intensity of 0.4W/cm², for three minutes, in 1, 8 and 24 hour after the injury. At these times, blood was drawn by venipuncture of the retroorbital plexus, for analysis of red and white blood cells. RESULTS: The CUS reduced erythrocytes in 8 percent at the first blood collection (9.9±0.1 versus 7.8±0.1; x10(5)/mm³; p<0.001); it doubled the number of segmented neutrophils at the second collection (3,166.8±161.4 versus 6,426.2±306.0; x10³/mm³; p=0.008) and the eosinophils at the third collection (2,883.6±99.0 versus 4,714.4±275.2; x10³/mm³; p=0.011), in relation to the CG. No differences between the groups were seen with regard to hematocrit, total leukocytes, rod neutrophils, monocytes or lymphocytes at the three times studied. CONCLUSIONS: Application of CUS for acute treatment of muscle injuries is contraindicated under this condition, because it promotes reductions in erythrocytes and increases in segmented neutrophils and eosinophils, thus favoring hemorrhage and increasing inflammatory process.