The level of mRNA encoding the amphotropic retrovirus receptor in mouse and human hematopoietic stem cells is low and correlates with the efficiency of retrovirus transduction.

The low level of amphotropic retrovirus-mediated gene transfer into human hematopoietic stem cells (HSC) has been a major impediment to gene therapy for hematopoietic diseases. In the present study, we have examined amphotropic retrovirus receptor (amphoR) and ecotropic retrovirus receptor mRNA expression in highly purified populations of mouse and human HSC. Murine HSC with low to undetectable levels of amphoR mRNA and relatively high levels of ecotropic retrovirus receptor mRNA were studied. When these HSC were analyzed simultaneously for ecotropic and amphotropic retrovirus transduction, ecotropic provirus sequences were detected in 10 of 13 long-term repopulated animals, while amphotropic proviral sequences were detected in only one recipient. A second distinct population of murine HSC were isolated that express 3-fold higher levels of amphoR mRNA. When these HSC were analyzed simultaneously for ecotropic and amphotropic retrovirus transduction, 11 of 11 repopulated mice contained ecotropic provirus and 6 of 11 contained amphotropic provirus sequences, a significant increase in the amphotropic retrovirus transduction (P = 0.018). These results indicate that, among the heterogeneous populations of HSC present in adult mouse bone marrow, the subpopulation with the highest level of amphoR mRNA is more efficiently transduced by amphotropic retrovirus. In a related study, we found low levels of human amphoR mRNA in purified populations of human HSC (CD34+ CD38-) and higher levels in committed progenitor cells (CD34+ CD38+). We conclude that the amphoR mRNA level in HSC correlates with amphotropic retrovirus transduction efficiency.

Reduction in the level of Gal(alpha1,3)Gal in transgenic mice and pigs by the expression of an alpha(1,2)fucosyltransferase.

Hyperacute rejection of a porcine organ by higher primates is initiated by the binding of xenoreactive natural antibodies of the recipient to blood vessels in the graft leading to complement activation. The majority of these antibodies recognize the carbohydrate structure Gal(alphal,3)Gal (gal epitope) present on cells of pigs. It is possible that the removal or lowering of the number of gal epitopes on the graft endothelium could prevent hyperacute rejection. The Gal(alpha1,3) Gal structure is formed by the enzyme Galbeta1,4GlcNAc3-alpha-D-galactosyltransferase [alpha(1,3)GT; EC 2.4.1.51], which transfers a galactose molecule to terminal N-acetyllactosamine (N-lac) present on various glycoproteins and glycolipids. The N-lac structure might be utilized as an acceptor by other glycosyltransferases such as Galbeta1,4GlcNAc 6-alpha-D-sialyltransferase [alpha(2,6)ST], Galbeta1,4GlcNAc 3-alpha-D-Sialyltransferase [alpha(2,3)ST], or Galbeta 2-alpha-L-fucosyltransferase [alpha(1,2)FT; EC 2.4.1.691, etc. In this report we describe the competition between alpha(1,2)FT and alpha(1,3)GT in cells in culture and the generation of transgenic mice and transgenic pigs that express alpha(1,2)Fr leading to synthesis of Fucalpha,2Galbeta- (H antigen) and a concomitant decrease in the level of Gal(alpha1,3)Gal. As predicted, this resulted in reduced binding of xenoreactive natural antibodies to endothelial cells of transgenic mice and protection from complement mediated lysis.

Systemic versus cartilage-specific expression of a type II collagen-specific T-cell epitope determines the level of tolerance and susceptibility to arthritis.

Immunization of mice with rat type II collagen (CII), a cartilage-specific protein, leads to development of collagen-induced arthritis (CIA), a model for rheumatoid arthritis. To define the interaction between the immune system and cartilage, we produced two sets of transgenic mice. In the first we point mutated the mouse CII gene to express an earlier defined T-cell epitope, CII-(256-270), present in rat CII. In the second we mutated the mouse type I collagen gene to express the same T-cell epitope. The mice with mutated type I collagen showed no T-cell reactivity to rat CII and were resistant to CIA. Thus, the CII-(256-270) epitope is immunodominant and critical for development of CIA. In contrast, the mice with mutated CII had an intact B-cell response and had T cells which could produce gamma interferon, but not proliferate, in response to CII. They developed CIA, albeit with a reduced incidence. Thus, we conclude that T cells recognize CII derived from endogenous cartilage and are partially tolerized but may still be capable of mediating CIA.

Enhancers increase the probability but not the level of gene expression.

We have studied enhancer function in transient and stable expression assays in mammalian cells by using systems that distinguish expressing from nonexpressing cells. When expression is studied in this way, enhancers are found to increase the probability of a construct being active but not the level of expression per template. In stably integrated constructs, large differences in expression level are observed but these are not related to the presence of an enhancer. Together with earlier studies, these results suggest that enhancers act to affect a binary (on/off) switch in transcriptional activity. Although this idea challenges the widely accepted model of enhancer activity, it is consistent with much, if not all, experimental evidence on this subject. We hypothesize that enhancers act to increase the probability of forming a stably active template. When randomly integrated into the genome, enhancers may affect a metastable state of repression/activity, permitting expression in regions that would not permit activity of an isolated promoter.

Level of involvement of clinical nurses in the evaluation of competence of nursing students

Objective. To determine the level of involvement of clinical nurses accredited by the Universitat Jaume I (Spain) as mentors of practice (Reference Nurses) in the evaluation of competence of nursing students. Methodolgy. Cross-sectional study, in which the “Clinical Practice Assessment Manual” (CPAM) reported by reference 41 nurses (n=55) were analyzed. Four quality criteria for completion were established: with information at least 80% of the required data, the presence of the signature and final grade in the right place. Verification of learning activities was also conducted. Data collection was performed concurrently reference for nurses and teachers of the subjects in the formative evaluations of clinical clerkship period in the matter “Nursing Care in Healthcare Processes “, from March to June 2013. Results. 63% of CPAM were completed correctly, without reaching the quality threshold established (80%). The absence of the signature is the main criteria of incorrect completion (21%). Nine learning activities do not meet the quality threshold set (80%) (p < 0.05). There are significant differences according to clinical units p < 0.05. From the 30 learning activities evaluated in the CPAM, it can be stated that nine of them do not reach the verification threshold established (80%), therefore it cannot be assumed that these activities had been completed by students and evaluated by the RefN throughout the clinical clerkship period. Conclusion. The level of involvement of Reference Nurse cannot be considered adequate, although strategies to encourage involvement through collaboration and training must be developed.

Factors that determine the level of commitment of our teaching staff when the implementation of continuous evaluation system takes place

Comunicación presentada en CIDUI 2010, Congreso Internacional Docencia Universitaria e Innovación, Barcelona, 30 junio-2 julio 2010.

The acceptable level of risk-taking for traditional rock climbers

Taking risk with all the consequences inevitably belongs to climbing. Each climber confronts his or her skills with the route he or she has chosen for an ascent. If the route is well protected, the rate of risk the climber takes is lower. If the route is less protected, the level of risk that the climber is exposed to proportionally increases. The aim of the research is to determine the level of risk-taking in traditional climbing on sandstone. We focus on how the level of risk affects climber’s performance and what reserve a climber needs to be able to cope with the higher risk and reduce it? The problem is solved by methods of quantitative research and the sample comprises more than 300 respondents. The results of the research prove a significant difference of climbers’ performance in dependence on rate of risk. Climbers usually reach lower performance according to the grading scale when climbing traditional routes with a higher level of risk.

How Does Intimate Partner Violence Differ Depending on Level of Rurality of Residential Area in Spain?

Intimate partner violence (IPV) is recognized as a worldwide public health problem. Most theories ascribe IPV to individual, family, or cultural factors. Authors analyzed different residential areas in Spain in terms of IPV frequency as well as its impact on health and the use of services. A standardized self-administered cross-sectional survey was administered to ever-partnered adult women ages 18 to 70 years receiving care at primary health care centers (N = 10,322). Logistic regression analyzed the association between the level of rurality and health indicators, IPV, and use of services. The lowest frequency of IPV among women is reflected in higher rurality. Women of medium and low rurality presented a poorer self-perceived health and more physical health problems. Women from medium and low rurality areas declared seeking health services more frequently. These results show the importance of the environment in health and indicate the need for research on urban–rural differences in health problems to develop specific public health programs for each country.