436 research outputs found

    SPECIFIC TRANSPLANTATION ANTIGENS OF MOUSE SARCOMAS INDUCED BY ADENOVIRUS TYPE 12

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    A specific isograft resistance against three different mouse adeno 12 sarcomas was demonstrated in mice treated with four to eight doses of viable or X-ray-killed adeno 12 mouse tumors. Whole-body X-ray irradiation with 350 R 24 hr previous to the test challenge did not abolish the resistance, indicating that it was due to a true anamnestic immune reaction. This was further proven by the finding that similar treatment with tumors of other origin did not induce any immunity, nor did the treatment with adeno 12 tumor material induce any immunity against two neoplasms of Schmidt-Ruppin-Rous viral origin. The previous report by Trentin et al. (17) that adeno 12 infection leads to a specific transplantation immunity was fully confirmed. When the specificity of this virus-induced immunity was studied it was discovered that besides adeno virus type 12, type 7 and probably type 18 also gave the same type of resistance while adenovirus type 5 did not. A contamination of the adeno 7-infected mice with adeno type 12 was excluded by testing pooled sera from these animals for anti-adeno 12 CF or HI antibodies

    Effects of AMPK activation on insulin sensitivity and metabolism in leptin-deficient ob/ob mice

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    AMP-activated protein kinase (AMPK) is a heterotrimeric complex, composed of a catalytic subunit (α) and two regulatory subunits (β and γ), which act as a metabolic sensor to regulate glucose and lipid metabolism. A mutation in the γ3 subunit (AMPKγ3(R225Q)) increases basal AMPK phosphorylation, while concomitantly reducing sensitivity to AMP. AMPKγ3(R225Q) (γ3(R225Q)) transgenic mice are protected against dietary-induced triglyceride accumulation and insulin resistance. We determined whether skeletal muscle-specific expression of AMPKγ3(R225Q) prevents metabolic abnormalities in leptin-deficient ob/ob (ob/ob-γ3(R225Q)) mice. Glycogen content was increased, triglyceride content was decreased, and diacylglycerol and ceramide content were unaltered in gastrocnemius muscle from ob/ob-γ3(R225Q) mice, whereas glucose tolerance was unaltered. Insulin-stimulated glucose uptake in extensor digitorum longus muscle during the euglycemic-hyperinsulinemic clamp was increased in lean γ3(R225Q) mice, but not in ob/ob-γ3(R225Q) mice. Acetyl-CoA carboxylase phosphorylation was increased in gastrocnemius muscle from γ3(R225Q) mutant mice independent of adiposity. Glycogen and triglyceride content were decreased after leptin treatment (5 days) in ob/ob mice, but not in ob/ob-γ3(R225Q) mice. In conclusion, metabolic improvements arising from muscle-specific expression of AMPKγ3(R225Q) are insufficient to ameliorate insulin resistance and obesity in leptin-deficient mice. Central defects due to leptin deficiency may override any metabolic benefit conferred by peripheral overexpression of the AMPKγ3(R225Q) mutation

    Metastable Dynamics above the Glass Transition

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    The element of metastability is incorporated in the fluctuating nonlinear hydrodynamic description of the mode coupling theory (MCT) of the liquid-glass transition. This is achieved through the introduction of the defect density variable nn into the set of slow variables with the mass density ρ\rho and the momentum density g{\bf g}. As a first approximation, we consider the case where motions associated with nn are much slower than those associated with ρ\rho. Self-consistently, assuming one is near a critical surface in the MCT sense, we find that the observed slowing down of the dynamics corresponds to a certain limit of a very shallow metastable well and a weak coupling between ρ\rho and nn. The metastability parameters as well as the exponents describing the observed sequence of time relaxations are given as smooth functions of the temperature without any evidence for a special temperature. We then investigate the case where the defect dynamics is included. We find that the slowing down of the dynamics corresponds to the system arranging itself such that the kinetic coefficient γv\gamma_v governing the diffusion of the defects approaches from above a small temperature-dependent value γvc\gamma^c_v.Comment: 38 pages, 14 figures (6 figs. are included as a uuencoded tar- compressed file. The rest is available upon request.), RevTEX3.0+eps

    Social- and Health Care Educators’ Cultural Competence

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    Introduction and aim: Cultural differences have significant impacts on classroom behaviours and communication in teaching. The aim of this study is to explore social and healthcare educators’ cultural competence in transcultural education. Methodology: Data was collected from semi-structured focus group interviews at universities of applied sciences and vocational colleges. Inductive content analysis was used in the analysis process. Results: Educators’ cultural competence in transcultural education emerges as generic categories: transcultural education, educatorship and ethical attitudes, and underpins by the sub-categories: language and linguistics, different learning styles, integrating multicultural students, cultural knowledge and sensitivity, collaborating and cooperating, self-awareness and openness, and respecting and caring. Conclusion: Cultural competence represents a core competence for social-and health care educators. Educators need to know students’ background, master different learning styles, be flexible in their pedagogical approaches and have an open and ethical attitude.  </p

    Qualitative study of social and healthcare educators' perceptions of their competence in education

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    Competent educators are needed to ensure that social and healthcare professionals are effective and highly competent. However, there is too little evidence-based knowledge of current and required enhancements of educators' competences in this field. The aim of this study was to describe social and healthcare educators' perceptions of their competence in education. The study had a qualitative design, based on interviews with educators and rooted in critical realism. Forty-eight participants were recruited from seven universities of applied sciences and two vocational colleges in Finland, with the assistance of contact persons nominated by the institutions. The inclusion criterion for participation was employment by an educational institution as a part-time or full-time, social and/or healthcare educator. Data were collected in the period February-April 2018. The participants were interviewed in 16 focus groups with two to five participants per group. The acquired data were subjected to inductive content analysis, which yielded 506 open codes, 48 sub-categories, nine categories and one main category. The educators' competence was defined as a multidimensional construct, including categories of educators' competences in practicing as an educator, subject, ethics, pedagogy, management and organisation, innovation and development, collaboration, handling cultural and linguistic diversity, and continuous professional development. Educators recognised the need for developing competence in innovation to meet rapid changes in a competitive and increasingly global sociopolitical environment. Enhancement of adaptability to rapid changes was recognised as a necessity. The findings have social value in identifying requirements to improve social and healthcare educators' competence by helping educational leadership to improve educational standards, construct a continuous education framework and create national and/or international curricula for teacher education degree programs to enhance the quality of education. We also suggest that educational leadership needs to establish, maintain and strengthen collaborative strategies to provide effective, adaptable support systems, involving educators and students, in their working practices

    Reduced CSF turnover and decreased ventricular Aβ42 levels are related

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    International audienceBACKGROUND: The appearance of Aβ42 peptide deposits is admitted to be a key event in the pathogenesis of Alzheimer's disease, although amyloid deposits also occur in aged non-demented subjects. Aβ42 is a degradation product of the amyloid protein precursor (APP). It can be catabolized by several enzymes, reabsorbed by capillaries or cleared into cerebrospinal fluid (CSF). The possible involvement of a decrease in CSF turnover in A4β2 deposit formation is up to now poorly known. We therefore investigated a possible relationship between a reduced CSF turnover and the CSF levels of the A4β2 peptide.To this aim, CSF of 31 patients with decreased CSF turnover were studied. These patients presented chronic hydrocephalus communicating or obstructive, which required surgery (ventriculostomy or ventriculo-peritoneal shunt). Nine subjects had idiopathic normal pressure hydrocephalus (iNPH), and the other 22 chronic hydrocephalus from other origins (oCH).The Aβ42 peptide concentration was measured by an ELISA test in 31 ventricular CSF samples and in 5 lumbar CSF samples from patients with communicating hydrocephalus. RESULTS: The 5 patients with lumbar CSF analysis had similar levels of lumbar and ventricular Aβ42. A significant reduction in Aβ42 ventricular levels was observed in 24 / 31 patients with hydrocephalus. The values were lower than 300 pg/ml in 5 out of 9 subjects with iNPH, and in 15 out of 22 subjects with oCH. CONCLUSION: The decrease of CSF Aβ42 seems to occur independently of the surgical hydrocephalus aetiology. This suggests that a CSF reduced turnover may play an important role in the decrease of CSF Aβ42 concentration

    The Effect of Iron Oxide Magnetic Nanoparticles on Smooth Muscle Cells

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    Recently, magnetic nanoparticles of iron oxide (Fe3O4, γ-Fe2O3) have shown an increasing number of applications in the field of biomedicine, but some questions have been raised about the potential impact of these nanoparticles on the environment and human health. In this work, the three types of magnetic nanoparticles (DMSA-Fe2O3, APTS-Fe2O3, and GLU-Fe2O3) with the same crystal structure, magnetic properties, and size distribution was designed, prepared, and characterized by transmission electronic microscopy, powder X-ray diffraction, zeta potential analyzer, vibrating sample magnetometer, and Fourier transform Infrared spectroscopy. Then, we have investigated the effect of the three types of magnetic nanoparticles (DMSA-Fe2O3, APTS-Fe2O3, and GLU-Fe2O3) on smooth muscle cells (SMCs). Cellular uptake of nanoparticles by SMC displays the dose, the incubation time and surface property dependent patterns. Through the thin section TEM images, we observe that DMSA-Fe2O3is incorporated into the lysosome of SMCs. The magnetic nanoparticles have no inflammation impact, but decrease the viability of SMCs. The other questions about metabolism and other impacts will be the next subject of further studies

    Reduced Bone Mass and Muscle Strength in Male 5α-Reductase Type 1 Inactivated Mice

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    Androgens are important regulators of bone mass but the relative importance of testosterone (T) versus dihydrotestosterone (DHT) for the activation of the androgen receptor (AR) in bone is unknown. 5α-reductase is responsible for the irreversible conversion of T to the more potent AR activator DHT. There are two well established isoenzymes of 5α-reductase (type 1 and type 2), encoded by separate genes (Srd5a1 and Srd5a2). 5α-reductase type 2 is predominantly expressed in male reproductive tissues whereas 5α-reductase type 1 is highly expressed in liver and moderately expressed in several other tissues including bone. The aim of the present study was to investigate the role of 5α-reductase type 1 for bone mass using Srd5a1−/− mice. Four-month-old male Srd5a1−/− mice had reduced trabecular bone mineral density (−36%, p<0.05) and cortical bone mineral content (−15%, p<0.05) but unchanged serum androgen levels compared with wild type (WT) mice. The cortical bone dimensions were reduced in the male Srd5a1−/− mice as a result of a reduced cortical periosteal circumference compared with WT mice. T treatment increased the cortical periosteal circumference (p<0.05) in orchidectomized WT mice but not in orchidectomized Srd5a1−/− mice. Male Srd5a1−/− mice demonstrated a reduced forelimb muscle grip strength compared with WT mice (p<0.05). Female Srd5a1−/− mice had slightly increased cortical bone mass associated with elevated circulating levels of androgens. In conclusion, 5α-reductase type 1 inactivated male mice have reduced bone mass and forelimb muscle grip strength and we propose that these effects are due to lack of 5α-reductase type 1 expression in bone and muscle. In contrast, the increased cortical bone mass in female Srd5a1−/− mice, is an indirect effect mediated by elevated circulating androgen levels
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