567 research outputs found
Correction: optimized labeling of bone marrow mesenchymal cells with superparamagnetic iron oxide nanoparticles and in vivo visualization by magnetic resonance imaging
Abstract Background Stem cell therapy has emerged as a promising addition to traditional treatments for a number of diseases. However, harnessing the therapeutic potential of stem cells requires an understanding of their fate in vivo. Non-invasive cell tracking can provide knowledge about mechanisms responsible for functional improvement of host tissue. Superparamagnetic iron oxide nanoparticles (SPIONs) have been used to label and visualize various cell types with magnetic resonance imaging (MRI). In this study we performed experiments designed to investigate the biological properties, including proliferation, viability and differentiation capacity of mesenchymal cells (MSCs) labeled with clinically approved SPIONs. Results Rat and mouse MSCs were isolated, cultured, and incubated with dextran-covered SPIONs (ferumoxide) alone or with poly-L-lysine (PLL) or protamine chlorhydrate for 4 or 24 hrs. Labeling efficiency was evaluated by dextran immunocytochemistry and MRI. Cell proliferation and viability were evaluated in vitro with Ki67 immunocytochemistry and live/dead assays. Ferumoxide-labeled MSCs could be induced to differentiate to adipocytes, osteocytes and chondrocytes. We analyzed ferumoxide retention in MSCs with or without mitomycin C pretreatment. Approximately 95% MSCs were labeled when incubated with ferumoxide for 4 or 24 hrs in the presence of PLL or protamine, whereas labeling of MSCs incubated with ferumoxide alone was poor. Proliferative capacity was maintained in MSCs incubated with ferumoxide and PLL for 4 hrs, however, after 24 hrs it was reduced. MSCs incubated with ferumoxide and protamine were efficiently visualized by MRI; they maintained proliferation and viability for up to 7 days and remained competent to differentiate. After 21 days MSCs pretreated with mitomycin C still showed a large number of ferumoxide-labeled cells. Conclusions The efficient and long lasting uptake and retention of SPIONs by MSCs using a protocol employing ferumoxide and protamine may be applicable to patients, since both ferumoxides and protamine are approved for human use.</p
Cancer Appetite and Symptom Questionnaire (CASQ) for Brazilian Patients: Cross-Cultural Adaptation and Validation Study
Background
Appetite and symptoms, conditions generally reported by the patients with cancer, are
somewhat challenging for professionals to measure directly in clinical routine (latent conditions).
Therefore, specific instruments are required for this purpose. This study aimed to perform
a cultural adaptation of the Cancer Appetite and Symptom Questionnaire (CASQ), into
Portuguese and evaluate its psychometric properties on a sample of Brazilian cancer
patients.
Methods
This is a validation study with Brazilian cancer patients. The face, content, and construct
(factorial and convergent) validities of the Cancer Appetite and Symptom Questionnaire,
the study tool, were estimated. Further, a confirmatory factor analysis (CFA) was conducted.
The ratio of chi-square and degrees of freedom (χ2
/df), comparative fit index (CFI),
goodness of fit index (GFI) and root mean square error of approximation (RMSEA) were
used for fit model assessment. In addition, the reliability of the instrument was estimated
using the composite reliability (CR) and Cronbach’s alpha coefficient (α), and the invariance
of the model in independent samples was estimated by a multigroup analysis (Δχ2).
Results
Participants included 1,140 cancer patients with a mean age of 53.95 (SD = 13.25) years;
61.3% were women. After the CFA of the original CASQ structure, 2 items with inadequate
factor weights were removed. Four correlations between errors were included to provide
adequate fit to the sample (χ2
/df = 8.532, CFI = .94, GFI = .95, and RMSEA = .08). Themodel exhibited a low convergent validity (AVE = .32). The reliability was adequate
(CR = .82 α = .82). The refined model showed strong invariance in two independent samples
(Δχ2
: λ: p = .855; i: p = .824; Res: p = .390). A weak stability was obtained between
patients undergoing chemotherapy and radiotherapy (Δχ2
: λ: p = .155; i: p < .001; Res:
p < .001), and between patients undergoing chemotherapy combined with radiotherapy
and palliative care (Δχ2
: λ: p = .058; i: p < .001; Res: p < .001).
Conclusion
The Portuguese version of the CASQ had good face and construct validity and reliability.
However, the CASQ still presented invariance in independent samples of Brazilian patients
with cancer. However, the tool has low convergent validity and weak invariance in samples
with different treatment
Study of expanded austenite formed in plasma nitrided AISI 316L samples, using synchrotron radiation diffraction
Comparative study on the use of specific and heterologous microsatellite primers in the stingless bees Melipona rufiventris and M. mondury (Hymenoptera, Apidae)
Due to their high degree of polymorphism, microsatellites are considered useful tools for studying population genetics. Nevertheless, studies of genetic diversity in stingless bees by means of these primers have revealed a low level of polymorphism, possibly the consequence of the heterologous primers used, since in most cases these were not specifically designed for the species under consideration. Herein we compared the number of polymorphic loci and alleles per locus, as well as observed heterozygosity in Melipona rufiventris and M. mondury populations, using specific and heterologous primers. The use of specific primers placed in evidence the greater frequency of polymorphic loci and alleles per locus, besides an expressive increase in observed heterozygosity in M. rufiventris and M. mondury, thereby reinforcing the idea that populational studies should be undertaken by preferably using species-specific microsatellite primers
Poor youths and ‘pacification’:dilemmas between discourse and practice from the perspective of young people about policing in Rio de Janeiro’s favelas
Ten years of Ana: lessons from a transdisciplinary body of literature on online pro-eating disorder websites
This paper offers a methodical review of the scientific literature of the last decade that concerns itself with online services offering supportive advocacy for anorexia nervosa and bulimia nervosa (‘pro-ana’ and ‘pro-mia’). The main question is whether these studies reproduce the traditional divide in the study of eating disorders, between clinical and social science perspectives, with limited mutual exchanges. Having first identified a specific body of literature, the authors investigate its content, methods and approaches, and analyse the network of cross-citations the components generate and share. On this basis, the authors argue that the scientific literature touching on pro-ana websites can be regarded as a single
transdisciplinary body of knowledge. What’s more, they show that the literature on computermediated sociabilities centred on eating disorders displays different structural characteristics with respect to the traditional, non-Web-related research on eating disorders. In the latter, the social sciences have usually provided a critical counterpoint to the development of a health sciences mainstream. In the case of Web-related research, however, the social sciences have taken the lead role in defining the field, with the health sciences following suit
A novel case of human visceral leishmaniasis from the urban area of the city of Rio de Janeiro: autochthonous or imported from Spain ?
Cytogenetic characterization of Partamona cupira (Hymenoptera, Apidae) by fluorochromes
Four colonies of the stingless bee Partamona cupira (Hymenoptera: Apidae) were cytogenetically analyzed using conventional staining and the fluorochromes CMA3 e DAPI. The females have 2n = 34 chromosomes (2K = 32
M¯+2
A¯). Some females, however, presented an additional large B acrocentric chromosome, to a total of 2n = 35. Chromosome B and the chromosomal pairs 2, 9 and 10 showed CMA 3+ bands, indicating an excess of CG base-pairs. A clear association was verified between the P. helleri B chromosome SCAR marker and the presence of a B chromosome in P. cupira. The data obtained suggests that B chromosomes in P. helleri and P. cupira share a common origin
Genomic selection in commercial perennial crops: applicability and improvement in oil palm (Elaeis guineensis Jacq.)
Genomic selection (GS) uses genome-wide markers to select individuals with the desired overall combination of breeding traits. A total of 1,218 individuals from a commercial population of Ulu Remis x AVROS (UR x AVROS) were genotyped using the OP200K array. The traits of interest included: shellto- fruit ratio (S/F, %), mesocarp-to-fruit ratio (M/F, %), kernel-to-fruit ratio (K/F, %), fruit per bunch (F/B, %), oil per bunch (O/B, %) and oil per palm (O/P, kg/palm/year). Genomic heritabilities of these traits were estimated to be in the range of 0.40 to 0.80. GS methods assessed were RR-BLUP, Bayes A (BA), Cπ (BC), Lasso (BL) and Ridge Regression (BRR). All methods resulted in almost equal prediction accuracy. The accuracy achieved ranged from 0.40 to 0.70, correlating with the heritability of traits. By selecting the most important markers, RR-BLUP B has the potential to outperform other methods. The marker density for certain traits can be further reduced based on the linkage disequilibrium (LD). Together with in silico breeding, GS is now being used in oil palm breeding programs to hasten parental palm selection
Genomic breeding value prediction using three Bayesian methods and application to reduced density marker panels
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