High resolution micro arthrography of hard and soft tissues in a murine model

SummaryObjectiveRecent developments on high resolution micro computed tomography (μCT) allow imaging of soft tissues in small animal joints. Nevertheless, μCT images cannot distinguish soft tissues from synovial fluid due to their similar mass density, limiting the 3D assessment of soft tissues volume and thickness. This study aimed to evaluate a lead chromate contrast agent for μCΤ arthrography of rat knee joints ex vivo.DesignIntact tibiofemoral rat joints were injected with the contrast agent at different concentrations and imaged using a μCT at 2.7 μm isotropic voxel size. Cartilage thickness was measured using an automated procedure, validated against histological measurements, and analyzed as a function of μCT image resolution. Changes in hard and soft tissues were also analyzed in tibiofemoral joints 4 weeks after surgical destabilization of the medial meniscus (DMM).ResultsThe contrast agent diffused well throughout the whole knee cavity without penetrating the tissues, therefore providing high contrast at the boundaries between soft tissues and synovial fluid space. Thickness analysis of cartilage demonstrated a high similarity between histology and μ-arthrography approaches (R2 = 0.90). Four weeks after surgical DMM, the development of osteophytes (Oph) and cartilage ulcerations was recognizable with μCT, as well as a slight increase in trabecular bone porosity, and decrease in trabecular thickness.ConclusionsA lead chromate-based contrast agent allowed discriminating the synovial fluid from soft tissues of intact knee joints, and thus made possible both qualitative and quantitative assessment of hard and soft tissues in both intact and DMM tibiofemoral joints using high resolution μCT

Magnetic states of granular layered CoFe-Al\u3csub\u3e2\u3c/sub\u3eO\u3csub\u3e3\u3c/sub\u3e

The granular layered magnetic system Co80Fe20(t)/Al2 O3 (3 nm), where the Co80Fe20 layers of nominal thickness t form separate, almost spherical magnetic granules of typical diameter 2-3 nm between the Al2O3 spacers, was studied. We discuss measurements of the dc and ac magnetic susceptibility χ for 1 n

Diversity and nitrogen fixation efficiency of rhizobia isolated from nodules of Centrolobium paraense

The objective of this work was to isolate and characterize rhizobia from nodules of Centrolobium paraense and to evaluate their symbiotic efficiency. Soil samples collected from four sites of the Roraima Cerrado, Brazil, were used to cultivate C. paraense in order to obtain nodules. Isolates (178) were obtained from 334 nodules after cultivation on medium 79. Twenty-five isolates belonging to six morphological groups were authenticated using Vigna unguiculata and they were characterized by 16S rRNA. Isolates identified as Bradyrhizobium were further characterized using rpoB gene sequencing. A greenhouse experiment was carried out with C. paraense to test the 18 authenticated isolates. Approximately 90% of the isolates grew slowly in medium 79. The 16S rRNA analysis showed that 14 authenticated isolates belong to the genus Bradyrhizobium, and rpoB indicated they constitute different groups compared to previously described species. Only four of the 11 fast-growing isolates nodulated V. unguiculata, two of which belong to Rhizobium, and two to Pleomorphomonas, which was not previously reported as a nodulating genus. The Bradyrhizobium isolates ERR 326, ERR 399, and ERR 435 had the highest symbiotic efficiency on C. paraense and showed a contribution similar to the nitrogen treatment. Centrolobium paraense is able to nodulate with different rhizobium species, some of which have not yet been described

Small bowel enteroscopy - A joint clinical guideline from the spanish and portuguese small bowel study groups

The present evidence-based guidelines are focused on the use of device-assisted enteroscopy in the management of small-bowel diseases. A panel of experts selected by the Spanish and Portuguese small bowel study groups reviewed the available evidence focusing on the main indications of this technique, its role in the management algorithm of each indication and on its diagnostic and therapeutic yields. A set of recommendations were issued accordingly.Estas recomendações baseadas na evidência detalham o uso da enteroscopia assistida por dispositivo no manejo clínico das doenças do intestino delgado. Um conjunto de Gastrenterologistas diferenciados em patologia do intestino delgado foi selecionado pelos grupos de estudos Espanhol e Português de intestino delgado para rever a evidência disponível sobre as principais indicações desta técnica, o seu papel nos algoritmos de manejo de cada indicação e sobre o seu rendimento diagnóstico e terapêutico. Foi gerado um conjunto de recomendações pelos autores