Competition-colonization dynamics in an RNA virus

During replication, RNA viruses rapidly generate diverse mutant progeny which differ in their ability to kill host cells. We report that the progeny of a single RNA viral genome diversified during hundreds of passages in cell culture and self-organized into two genetically distinct subpopulations that exhibited the competition-colonization dynamics previously recognized in many classical ecological systems. Viral colonizers alone were more efficient in killing cells than competitors in culture. In cells coinfected with both competitors and colonizers, viral interference resulted in reduced cell killing, and competitors replaced colonizers. Mathematical modeling of this coinfection dynamics predicted selection to be density dependent, which was confirmed experimentally. Thus, as is known for other ecological systems, biodiversity and even cell killing of virus populations can be shaped by a tradeoff between competition and colonization. Our results suggest a model for the evolution of virulence in viruses based on internal interactions within mutant spectra of viral quasispecies.     

Magnetic resonance imaging of the entorhinal cortex and hippocampus in mild cognitive impairment and Alzheimer's disease

OBJECTIVES: To explore volume changes of the entorhinal cortex (ERC) and hippocampus in mild cognitive impairment (MCI) and Alzheimer's disease (AD) compared with normal cognition (NC); to determine the powers of the ERC and the hippocampus for discrimination between these groups. METHODS: This study included 40 subjects with NC, 36 patients with MCI, and 29 patients with AD. Volumes of the ERC and hippocampus were manually measured based on coronal T1 weighted MR images. Global cerebral changes were assessed using semiautomatic image segmentation. RESULTS: Both ERC and hippocampal volumes were reduced in MCI (ERC 13%, hippocampus 11%, p<0.05) and AD (ERC 39%, hippocampus 27%, p<0.01) compared with NC. Furthermore, AD showed greater volume losses in the ERC than in the hippocampus (p<0.01). In addition, AD and MCI also had cortical grey matter loss (p< 0.01) and ventricular enlargement (p<0.01) when compared with NC. There was a significant correlation between ERC and hippocampal volumes in MCI and AD (both p<0.001), but not in NC. Using ERC and hippocampus together improved discrimination between AD and CN but did not improve discrimination between MCI and NC. The ERC was better than the hippocampus for distinguishing MCI from AD. In addition, loss of cortical grey matter significantly contributed to the hippocampus for discriminating MCI and AD from NC. CONCLUSIONS: Volume reductions in the ERC and hippocampus may be early signs of AD pathology that can be measured using MRI.     

Bedside femoral block performed on the first postoperative day after unilateral total knee arthroplasty: a randomized study of 49 patients

This randomized study compared the effectiveness of a femoral nerve block with other methods of pain control on the first postoperative day after total knee arthroplasty. The femoral block consisted of a single injection administered at patients' bedside during the surgeon's hospital rounds. Compared with control group patients, femoral block patients reported less pain on a visual analog scale and required one half the amount of oxycodone (P = .021). Additional femoral block or continued epidural analgesia was required more frequently by control group patients. Thus, pain management with femoral blocks resulted in less work for nursing staff (P = .004). Performing a femoral nerve block as needed during the surgeon's hospital rounds is quick and requires minimal additional time without any special equipment. Bedside femoral block is a useful adjunct to other pain control methods following primary total knee arthroplasty.     

Transpersonal psychology -- psychology of consciousness: chances and problems

Transpersonal psychology represents a perspective which has gained importance in psychological research and clinical practice over the last years. This paper offers an overview on the history and the sources of transpersonal psychology. Additionally, important themes and topics of transpersonal psychology will be discussed such as a) the importance of spirituality in psychotherapy and counselling, b) spirituality as a resource for maintaining and regaining health, c) spiritual experiences as an avenue to consciousness, d) the delimination of extraordinary states of consciousness and "spiritual crises". In the next paragraph specific problems and critical points of transpersonal psychology are presented. Among them are the discussion of the question whether experience free of language is at all possible as well as the question how notions coming from eastern traditions can be translated into western psychology. Finally, some positive aspects of transpersonal psychology will be presented, and we submit that transpersonal psychology should be taken seriously in a scientific way.     

CD95/Fas expression on peripheral blood T lymphocytes in patients with multiple sclerosis: effect of high-dose methylprednisolone therapy

Recent data indicate that the apoptotic process, mediated by the CD95/Fas cell surface receptor, is impaired in activated lymphocytes of patients with relapsing-remitting multiple sclerosis. Using flow cytometric-immunophenotyping, we analyzed the expression of CD95/Fas on peripheral blood CD4+ and CD8+ T lymphocytes (PBL) in 10 MS patients in relapse, and the effect of pulse corticosteroid therapy on the apoptosis of autoreactive lymphocytes. The proportions of CD8+ and CD8+CD95+ T lymphocytes were significantly higher in MS patients in relapse before than after pulse corticosteroid therapy. Conversely, the proportions of CD4+ and CD4+CD95+ T cells were significantly lower before than after therapy, but not significantly different from healthy persons. The different expression of CD95/Fas on peripheral blood CD8+ T lymphocytes in relapsing RRMS and in healthy controls suggests a possible involvement of apoptosis in the pathogenesis of MS. Our results also show that pulse corticosteroid therapy influences the CD95/Fas expression on CD8+ and CD4+ T lymphocytes in patients with RRMS.     

Coronary heart disease prevention and lifestyle interventions: cultural influences

Unless action is directed to address the multiple influences on coronary heart disease (CHD) risk reduction behaviors, across all population groups, the aims of Healthy People 2010 with regard to CHD will not be realized. Health-promotion and disease-prevention models, including a framework for primordial, primary, and secondary prevention provided by an American Heart Association task force, and a model for interventions to eliminate health disparities are reviewed. The role of culture, ethnicity, race, and socioeconomic status and how these concepts have been studied in recent lifestyle interventions aimed at CHD risk reduction is explored. Finally, these findings are synthesized to provide suggestions for nursing care delivery in primary and tertiary care settings.     

Inhibition of receptor tyrosine kinase signalling by small molecule agonist of T-cell protein tyrosine phosphatase

Background  

T-cell protein tyrosine phosphatase (TCPTP/TC45) is a ubiquitously expressed intra-cellular non-receptor protein tyrosine phosphatase involved in the negative regulation of several cancer relevant cellular signalling pathways. We have previously shown that interaction between the α-cytoplasmic tail of α1β1 integrin and TCPTP activates TCPTP by disrupting an inhibitory intra-molecular bond in TCPTP. Thus, inhibition of the regulatory interaction in TCPTP is a desirable strategy for TCPTP activation and attenuation of oncogenic RTK signalling. However, this is challenging with low molecular weight compounds.