382 research outputs found
Skeletal Myogenic Progenitors Originating from Embryonic Dorsal Aorta Coexpress Endothelial and Myogenic Markers and Contribute to Postnatal Muscle Growth and Regeneration
Skeletal muscle in vertebrates is derived from somites, epithelial structures of the paraxial mesoderm, yet many unrelated reports describe the occasional appearance of myogenic cells from tissues of nonsomite origin, suggesting either transdifferentiation or the persistence of a multipotent progenitor. Here, we show that clonable skeletal myogenic cells are present in the embryonic dorsal aorta of mouse embryos. This finding is based on a detailed clonal analysis of different tissue anlagen at various developmental stages. In vitro, these myogenic cells show the same morphology as satellite cells derived from adult skeletal muscle, and express a number of myogenic and endothelial markers. Surprisingly, the latter are also expressed by adult satellite cells. Furthermore, it is possible to clone myogenic cells from limbs of mutant c-Met-/- embryos, which lack appendicular muscles, but have a normal vascular system. Upon transplantation, aorta-derived myogenic cells participate in postnatal muscle growth and regeneration, and fuse with resident satellite cells.
The potential of the vascular system to generate skeletal muscle cells may explain observations of nonsomite skeletal myogenesis and raises the possibility that a subset of satellite cells may derive from the vascular system
Clara Sereni, ovvero lāindecente differenza
Una vita a mosaico Nellāintroduzione al Taccuino di unāultimista Clara Sereni giustifica cosƬ il criterio secondo il quale, nella raccolta, sono stati ordinati i testi da lei scritti negli anniĀ ā80 e nella prima metĆ deiā90 per diverse riviste e quotidiani: Non fingo alle quattro partizioni di questo libro unāoggettivitĆ esterna, ma le dichiaro come i quattro spicchi dei quali, con continui sconfinamenti, mi sembra di compormi: ebrea per scelta piĆ¹ che per destino, donna non solo per lāanagra..
DEVELOPMENT OF ROCKET HYBRIDS (ERUCA SATIVA AND DIPLOTAXIS TENUIFOLIA) RESISTANT TO FUSARIUM OXYSPORUM FF.SPP. AND PHYTOPHTHORA PARASITICA
La rucola ĆØ una specie orticola coltivata a livello nazionale e di recente interesse per il miglioramento genetico vegetale. L'obiettivo generale del progetto era quello di sviluppare delle varietĆ o degli ibridi nuovi di questa specie, che fossero piĆ¹ adattabili alle esigenze di mercato. Le principali caratteristiche da perseguire erano le resistenze ai principali patogeni (Fusarium oxysporum e Hyalopernospora) e il miglioramento di aspetti qualitativi e di resa finale. Si ĆØ scelto di procedere attraverso tecniche di miglioramento genetico classico, analisi qualitative e di patologia vegetale.Rocket is an horticultural crop cultivated nationally and of recent interest for plant genetic improvement. The general objective of the project was to develop new varieties or hybrids of this crop, more adaptable to market requirements. The main characteristics to be pursued were resistance to the main pathogens (Fusarium oxysporum and Hyalopernospora) and the improvement of qualitative aspects and final yield. It was decided to proceed through classic genetic improvement techniques, qualitative analyzes and plant pathology assestments
Characterization of a synthetic bacterial self-destruction device for programmed cell death and for recombinant proteins release
<p>Abstract</p> <p>Background</p> <p>Bacterial cell lysis is a widely studied mechanism that can be achieved through the intracellular expression of phage native lytic proteins. This mechanism can be exploited for programmed cell death and for gentle cell disruption to release recombinant proteins when <it>in vivo </it>secretion is not feasible. Several genetic parts for cell lysis have been developed and their quantitative characterization is an essential step to enable the engineering of synthetic lytic systems with predictable behavior.</p> <p>Results</p> <p>Here, a BioBrickā¢ lysis device present in the Registry of Standard Biological Parts has been quantitatively characterized. Its activity has been measured in <it>E. coli </it>by assembling the device under the control of a well characterized N-3-oxohexanoyl-L-homoserine lactone (HSL) -inducible promoter and the transfer function, lysis dynamics, protein release capability and genotypic and phenotypic stability of the device have been evaluated. Finally, its modularity was tested by assembling the device to a different inducible promoter, which can be triggered by heat induction.</p> <p>Conclusions</p> <p>The studied device is suitable for recombinant protein release as 96% of the total amount of the intracellular proteins was successfully released into the medium. Furthermore, it has been shown that the device can be assembled to different input devices to trigger cell lysis in response to a user-defined signal. For this reason, this lysis device can be a useful tool for the rational design and construction of complex synthetic biological systems composed by biological parts with known and well characterized function. Conversely, the onset of mutants makes this device unsuitable for the programmed cell death of a bacterial population.</p
A standard vector for the chromosomal integration and characterization of BioBrickā¢ parts in Escherichia coli
BACKGROUND: The chromosomal integration of biological parts in the host genome enables the engineering of plasmid-free stable strains with single-copy insertions of the desired gene networks. Although different integrative vectors were proposed, no standard pre-assembled genetic tool is available to carry out this task. Synthetic biology concepts can contribute to the development of standardized and user friendly solutions to easily produce engineered strains and to rapidly characterize the desired genetic parts in single-copy context. RESULTS: In this work we report the design of a novel integrative vector that allows the genomic integration of biological parts compatible with the RFC10, RFC23 and RFC12 BioBrickā¢ standards in Escherichia coli. It can also be specialized by using BioBrickā¢ parts to target the desired integration site in the host genome. The usefulness of this vector has been demonstrated by integrating a set of BioBrickā¢ devices in two different loci of the E. coli chromosome and by characterizing their activity in single-copy. Construct stability has also been evaluated and compared with plasmid-borne solutions. CONCLUSIONS: Physical modularity of biological parts has been successfully applied to construct a ready-to-engineer BioBrickā¢ vector, suitable for a stable chromosomal insertion of standard parts via the desired recombination method, i.e. the bacteriophage integration mechanism or homologous recombination. In contrast with previously proposed solutions, it is a pre-assembled vector containing properly-placed restriction sites for the direct transfer of various formats of BioBrickā¢ parts. This vector can facilitate the characterization of parts avoiding copy number artefacts and the construction of antibiotic resistance-free engineered microbes, suitable for industrial use
Low-Power Ultrasounds as a Tool to Culture Human Osteoblasts inside Cancellous Hydroxyapatite
Bone graft substitutes and cancellous biomaterials have been widely used to heal critical-size long bone defects due to trauma, tumor resection, and tissue degeneration. In particular, porous hydroxyapatite is widely used in reconstructive bone surgery owing to its biocompatibility. In addition, the in vitro modification of cancellous hydroxyapatite with osteogenic signals enhances the tissue regeneration in vivo, suggesting that the biomaterial modification could play an important role in tissue engineering. In this study, we have followed a tissue-engineering strategy where ultrasonically stimulated SAOS-2 human osteoblasts proliferated and built their extracellular matrix inside a porous hydroxyapatite scaffold. The ultrasonic stimulus had the following parameters: average power equal to 149āmW and frequency of 1.5āMHz. In comparison with control conditions, the ultrasonic stimulus increased the cell proliferation and the surface coating with bone proteins (decorin, osteocalcin, osteopontin, type-I collagen, and type-III collagen). The mechanical stimulus aimed at obtaining a better modification of the biomaterial internal surface in terms of cell colonization and coating with bone matrix. The modified biomaterial could be used, in clinical applications, as an implant for bone repair
Efficacy and accuracy of maxillary arch expansion with clear aligner treatment
The aim of this work was to evaluate the efficacy and accuracy of maxillary arch transverse expansion using the InvisalignĀ® clear aligner system without auxiliaries other than Invisalign attachments. Knowing the accuracy of a movement through a clear aligner system allows the clinician to plan the treatment with greater precision and to achieve the expected result faster. The study group included 28 patients with a mean age of 17 Ā± 3.2 years. The treatment protocol for all the selected patients included the application of the InvisalignĀ® clear aligner system without auxiliaries, except for the InvisalignĀ® attachments; in no case were tooth extraction or interproximal enamel reduction (IPR) performed. Linear measurements of the expansion were assessed before treatment (T0), at the end of treatment (T1), and on final virtual models by ClinCheckĀ® (TC). A paired t-test was used to compare T0-T1 and T1-TC differences. A paired t-test was applied, and one normality was validated with the Shapiro-Wilks test. If normality was not met, the nonparametric test (Mann-Whitney U test) was applied. The level of significance was set at 5%. Statistically significant differences were found for all measurements at T0-T1. The results showed an average accuracy of efficacy of 70.88%. The differences in predictability between the various vestibular measurements (intercanine, inter-premolar, and intermolar) were not statistically significant, while they were for gingival measurements. The overall accuracy of the expansion treatment was 70%, regardless of tooth type
Evaluation of the effects of specific karate exercises during multilateral training in children of primary school
The early specialization in the development of sport skills is a point of discussion among researchers, even if the general trend is to encourage multilateral activities in children. The aim of this study was to evaluate the effect of specific karate exercises added during a program of multilateral exercises in a group of school age children. A sample of 82 primary school children (39 females, 6.4 Ā± 0.3 y and 43 males, 6.3 Ā± 0.3 y) were randomly assigned to two groups: Multilateral (MG) and Special (SG). MG was composed of 19 females (MGf, 6,4 Ā± 0,3 y) and 22 males (MGm, 6,3 Ā± 0,3 y), while SG was composed of 20 females (SGf, 6,3 Ā± 0,3 y) and 21 males (SGm, 6,4 Ā± 0,3 y). During the training period of eight weeks, the MG group has played only multilateral activities, while the SG group has also done specific exercises of Karate. At the end of the training period both groups were subjected to some physical evaluation test and the results was statistically analyzed (ANOVA). Although both groups (Mg and SG) have improved significantly (p < 0.05) compared to the initial stage, the comparison between the two groups (MG vs SG) has not revealed significant differences in relation to the considered motor skills (speed, agility, strength, coordination), with the exception of the ability of static balance, in which the SG group showed a significant improvement compared to the MG group (p = 0.019). In particular, the improvement appears to be due mainly to the female component (SGf vs MGf: p = 0,012; SGm vs MGm p = 0,20). The fact that the improvement was mainly dependent on the female group deserves future investigations The results seem to confirm the fact that the multilateral activities would be sufficient to improve motor skills in primary school children, although some neuromotor abilities could be improved through more specific exercises without creating particular damag
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