Chromosomal integrity maintained in five human embryonic stem cell lines after prolonged in vitro culture

There have been recent reports of human embryonic stem cell (hESC) lines developing chromosomal aberrations after long-term culture, indicating an unstable genomic status due to the in vitro milieu. This raises concern, since it would limit their use in therapeutics. In this study the chromosomal status of five well-characterized hESC lines, SA002, SA002.5, AS034.1.1, SA121 and SA461, was monitored during long-term in vitro culture. The criteria of defined hESCs were met by all of the five hESC lines (four diploid and one trisomic for chromosome 13). The genomes were screened for chromosomal aberrations and rearrangements using comparative genomic hybridization (CGH), interphase fluorescence in situ hybridization (FISH) and traditional karyotyping on several occasions while in culture. The genomic integrity was shown to be maintained after repeated freeze-thaw procedures and continuous culture in vitro for up to 22 months (148 passages). We discuss the most common de novo chromosomal aberrations reported in hESCs, as well as their possible origin.     

Cellular nonmuscle myosins NMHC‐IIA and NMHC‐IIB and vertebrate heart looping

Flectin, a protein previously described to be expressed in a left‐dominant manner in the embryonic chick heart during looping, is a member of the nonmuscle myosin II (NMHC‐II) protein class. During looping, both NMHC‐IIA and NMHC‐IIB are expressed in the mouse heart on embryonic day 9.5. The patterns of localization of NMHC‐IIB, rather than NMHC‐IIA in the mouse looping heart and in neural crest cells, are equivalent to what we reported previously for flectin. Expression of full‐length human NMHC‐IIA and ‐IIB in 10 T1/2 cells demonstrated that flectin antibody recognizes both isoforms. Electron microscopy revealed that flectin antibody localizes in short cardiomyocyte cell processes extending from the basal layer of the cardiomyocytes into the cardiac jelly. Flectin antibody also recognizes stress fibrils in the cardiac jelly in the mouse and chick heart; while NMHC‐IIB antibody does not. Abnormally looping hearts of the Nodal^{Δ 600} homozygous mouse embryos show decreased NMHC‐IIB expression on both the mRNA and protein levels. These results document the characterization of flectin and extend the importance of NMHC‐II and the cytoskeletal actomyosin complex to the mammalian heart and cardiac looping. Developmental Dynamics 237:3577–3590, 2008. © 2008 Wiley‐Liss, Inc.     

The self-reported use of research in clinical practice: A survey of occupational therapists in Sweden

Background: Today, healthcare providers and occupational therapists are increasingly required to rely on evidence-based practices. In both outpatient and inpatient settings, the use of research-based practices can be identified using the Research Utilization Measure questionnaire. Aim: This study explores how occupational therapists in Sweden perceive research utilization. Method: The Research Utilization Measure was sent to 807 randomly selected occupational therapists in Sweden, and the response rate was 59% (n = 472). Results: The majority of respondents (56%, n = 256) reported use of research-based knowledge in their practice “very or rather often”, although 49% (n = 225) of the therapists noted that they “very seldom or never” discussed research findings with their managers. Differences in answers for most items were related to degree of education and length of experience. Occupational therapists with higher education levels more often reported use of research in their clinical practice and therapists with greater experience less often reported use of research in their clinical practice. Conclusion: Education seems to influence the degree to which occupational therapists rely on research to inform their practices. A future challenge for managers and occupational therapists is to create strategic discussions on how to implement treatment that is based on current research.     

Effect of Low-Dose Aspirin on the Markers of Oxidative Stress

Summary. The present study estimates effects of low-dose enteric coated aspirin (ECA) on oxidative stress (OS) markers in a group of middle-aged men (mean age 51.2 ± 6.9 years) free of pre-existing ischemic heart disease.Methods. Serum products of lipid peroxidation, and measures of antioxidative status were detected in 25 healthy men in baseline and after two-week treatment period.Results. In respect to serum products of lipid peroxidation and markers of antioxidant status, no statistically significant differences between the pre- and after-treatment data were observed for any measures, with the exception of values of serum antioxidative capacity (39.0 ± 2.5 and 42 ± 4.6, respectively).Conclusions. Administration of ECA does not initiate the OS in blood and improves the general antioxidative potency of blood. This may imply towards certain antiatherogenic influence of low-dose ECA, exhibited even with a short-term treatment period. Regarding OS markers, a variety of individual responses observed in the selected subgroups should be investigated and possibly taken into account while treatment with ECA is initiated for primary prevention of cerebrovascular events.     

Altered mitochondrial metabolism in the insulin‐resistant heart

Obesity‐induced insulin resistance and type 2 diabetes mellitus can ultimately result in various complications, including diabetic cardiomyopathy. In this case, cardiac dysfunction is characterized by metabolic disturbances such as impaired glucose oxidation and an increased reliance on fatty acid (FA) oxidation. Mitochondrial dysfunction has often been associated with the altered metabolic function in the diabetic heart, and may result from FA‐induced lipotoxicity and uncoupling of oxidative phosphorylation. In this review, we address the metabolic changes in the diabetic heart, focusing on the loss of metabolic flexibility and cardiac mitochondrial function. We consider the alterations observed in mitochondrial substrate utilization, bioenergetics and dynamics, and highlight new areas of research which may improve our understanding of the cause and effect of cardiac mitochondrial dysfunction in diabetes. Finally, we explore how lifestyle (nutrition and exercise) and pharmacological interventions can prevent and treat metabolic and mitochondrial dysfunction in diabetes.     

Cumulative impact of adding frozen-thawed cycles to single versus double fresh embryo transfers

Randomized control trials have shown that single embryo transfer (SET) results in lower live birth rates than double embryo transfer (DET), while observational, retrospective studies find no decrease in overall live birth rate when using a SET policy. The cumulative (fresh transfer followed by frozen - thawed transfers of embryos from the same stimulated cycle) live birth rate after the first and the second stimulated cycle of SET and DET respectively has been analysed. All couples who received their first fresh embryo transfer at Sahlgrenska University Hospital during 2003 and 2004 were included (n = 689). The live birth rates after DET versus SET in the first and second fresh cycles were 29.7 (47/158) versus 23.9% (127/531) and 30.8 (41/133) versus 22.0% (45/205). The cumulative live birth rate per patient after the addition of frozen-thawed embryo transfers were similar: 33.5 (53/158) and 34.8% (185/531) for DET and SET respectively after the first cycle and 32.3 (43/133) versus 32.2% (66/205) after the second cycle. A logistic regression analysis showed no significant correlation for SET or DET with cumulative live birth. Thus, cumulative live birth rates are similar after SET and DET in a routine IVF programme with a majority of SET transfers, although a higher number of frozen-thawed cycles were needed in the SET group.     

Gut vernetzt oder aus dem Netz gefallen?

The article presents a practice-oriented instrument for the perception and analysis of complex situations, in which individuals, groups and organisations may find themselves. Findings from the economy, sociometry, and networking research have been gathered and made suitable for supervision and management consultation. The socio-dramatic network analysis presents a method for active diagnostics??in order to understand people within their social context, in their professional and social field, as colleagues, clients and customers. It may serve as a tool for a complex and effective understanding of problems and may offer insights to new coping strategies for individuals, groups, teams, departments and organisations. The theory and practice of the method are explicated and demonstrated through case studies from various professional contexts.