Calcineurin-Aα alpha activation enhances the structure and function of regenerating muscles after myotoxic injury

Calcineurin signaling is essential for successful muscle regeneration. Although calcineurin inhibition compromises muscle repair, it is not known whether calcineurin activation can enhance muscle repair after injury. Tibialis anterior (TA) muscles from adult wild-type (WT) and transgenic mice overexpressing the constitutively active calcineurin-Aα transgene under the control of the mitochondrial creatine kinase promoter (MCK-CnAα*) were injected with the myotoxic snake venom Notexin to destroy all muscle fibers. The TA muscle of the contralateral limb served as the uninjured control. Muscle structure was assessed at 5 and 9 days postinjury, and muscle function was tested in situ at 9 days postinjury. Calcineurin stimulation enhanced muscle regeneration and altered levels of myoregulatory factors (MRFs). Recovery of myofiber size and force-producing capacity was hastened in injured muscles of MCK-CnAα* mice compared with control. Myogenin levels were greater 5 days postinjury and myocyte enhancer factor 2a (MEF2a) expression was greater 9 days postinjury in muscles of MCK-CnAα* mice compared with WT mice. Higher MEF2a expression in regenerating muscles of MCK-CnAα* mice 9 days postinjury may be related to an increase of slow fiber genes. Calcineurin activation in uninjured and injured TA muscles slowed muscle contractile properties, reduced fatigability, and enhanced force recovery after 4 min of intermittent maximal stimulation. Therefore, calcineurin activation can confer structural and functional benefits to regenerating skeletal muscles, which may be mediated in part by differential expression of MRFs.

Activated calcineurin ameliorates contraction-induced injury to skeletal muscles of mdx dystrophic mice

Utrophin expression is regulated by calcineurin and up-regulating utrophin can decrease the susceptibility of dystrophic skeletal muscle to contraction-induced injury. We overexpressed the constitutively active calcineurin-A α in skeletal muscle of mdx dystrophic mice (mdx CnA*) and examined the tibialis anterior muscle to determine whether the presence of activated calcineurin promotes resistance to muscle damage after lengthening contractions. Two stretches (10 s apart) of 40% strain relative to muscle fibre length were initiated from the plateau of a maximal isometric tetanic contraction. Muscle damage was assessed 1, 5 and 15 min later by the deficit in maximum isometric force and by quantifying the proportion of muscle fibres staining positive for intracytoplasmic albumin. The force deficit at all time points after the lengthening contractions was approximately 80% in mdx muscles and 30% in mdxCnA* muscles. The proportion of albumin-positive fibres was significantly less in control and injured muscles from mdxCnA* mice than from mdx mice. Compared with mdx mice, mean fibre cross-sectional area was 50% less in muscles from mdxCnA* mice. Furthermore, muscles frommdxCnA* mice exhibited a higher proportion of fibres expressing the slow(er) myosin heavy chain (MyHC) I and IIa isoforms, prolonged contraction and relaxation times, lower absolute and normalized maximum forces, and a clear leftward shift of the frequency–force relationship with greater force production at lower stimulation frequencies. These are structural and functional markers of a slower muscle phenotype. Taken together, our findings show that muscles from mdxCnA* mice have a smaller mean fibre cross-sectional area, a greater sarcolemmal to cytoplasmic volume ratio, and an increase in utrophin expression, promoting an attenuated susceptibility to contraction-induced injury. We conclude that increased calcineurin activity may confer functional benefits to dystrophic skeletal muscles.

Effects of ovariectomy and estrogen on ischemia-reperfusion injury in hindlimbs of female rats

The effects of estrogen and ovariectomy on indexes of muscle damage after 2 h of complete hindlimb ischemia and 2 h of reperfusion were investigated in female Sprague-Dawley rats. The rats were assigned to one of three experimental groups: ovariectomized with a 17-estradiol pellet implant (OE), ovariectomized with a placebo pellet implant (OP), or control with intact ovaries (R). It was hypothesized that following ischemia-reperfusion (I/R), muscle damage indexes [serum creatine kinase (CK) activity, calpain-like activity, inflammatory cell infiltration, and markers of lipid peroxidation (thiobarbituric-reactive substances)] would be lower in the OE and R rats compared with the OP rats due to the protective effects of estrogen. Serum CK activity following I/R was greater (P < 0.01) in the R rats vs. OP rats and similar in the OP and OE rats. Calpain-like activity was greatest in the R rats (P < 0.01) and similar in the OP and OE rats. Neutrophil infiltration was assessed using the myeloperoxidase (MPO) assay and immunohistochemical staining for CD43-positive (CD43+) cells. MPO activity was lower (P < 0.05) in the OE rats compared with any other group and similar in the OP and R rats. The number of CD43+ cells was greater (P < 0.01) in the OP rats compared with the OE and R rats and similar in the OE and R rats. The OE rats had lower (P < 0.05) thiobarbituric-reactive substance content following I/R compared with the R and OP rats. Indexes of muscle damage were consistently attenuated in the OE rats but not in the R rats. A 10-fold difference in serum estrogen content may mediate this. Surprisingly, serum CK activity and muscle calpain-like activity were lower (P < 0.05) in the OP rats compared with the R rats. Increases in serum insulin-like growth factor-1 content (P < 0.05) due to ovariectomy were hypothesized to account for this finding. Thus both ovariectomy and estrogen supplementation have differential effects on indexes of I/R muscle damage.

Emotional intelligence and teaching : solving the puzzle

The emotional intelligence of educators has a major influence on how well they are able to help people to learn. Teachers with high levels of emotional intelligence always or usually adopt an appropriate emotionally intelligent response in both positive and negative situations. Teachers with low levels of emotional intelligence sometimes adopt an emotionally intelligent response in positive situations but seldom or never in negative situations. These differences have some significant implications. The authors' research shows that emotional intelligence and self-efficacy are different but related concepts. A teacher's level of emotional intelligence is linked to his or her sense of self-efficacy. A teacher with high levels of emotional intelligence is more likely to be able to work more effectively and persist longer because they have a belief in their own ability and feel that they are in control. The emotionally intelligent teacher is sensitive to his or her own emotions and the emotions of others and so is able to build positive relationships with colleagues and students. Beyond that, a teaching environment that is emotionally healthy and supportive will enhance the development of teachers' emotional intelligence.

Injury and burnout in Australian athletes

The relationship between injury and burnout in a sample of 264 local to international Australian athletes (124 men and 140 women) was studied. Injury can be a stressful experience for athletes; coupled with the demands of rehabilitation, it could increase feelings of burnout. Experiencing more than one injury could have a cumulative effect on feelings of burnout. Alternatively, for some athletes the break from training or competing caused by an injury could alleviate burnout symptoms. Participants completed a demographic questionnaire and a modified version of the Maslach Burnout Inventory. Independent sample t tests indicated that currently injured athletes (n = 150) had significantly lower mean Burnout scores than currently uninjured athletes (n = 113). Small, but statistically significant, positive correlations were found between number of injuries and Burnout scores. Possible explanations are that injury provides a temporary break from intense sporting involvement and, thus, lower scores on Burnout, but multiple injuries might have a cumulative effect on burnout.

The factorial validity of emotional intelligence : an unresolved issue

An unresolved but pertinent issue in the field of emotional intelligence (EI) is factorial validity. Numerous studies have investigated this issue (Gignac, 2005; Mayer, Salovey, Caruso, & Sitarenios, 2003; Petrides & Furnham, 2000; Saklofske, Austin, & Minski, 2003), but most are based on correlations among subscale scores from relevant measures, making the implicit assumption that subscale scores are unidimensional, rather than questioning the structure of subscales themselves. Accordingly, the present study adopts the Anderson and Gerbing (1988) two-step strategy of first considering the structure within subscales before examining the relationship between subscales. An evaluation was undertaken using the Emotional Intelligence Scale (EIS, Schutte et al., 1998), the Work Profile Questionnaire – Emotional Intelligence Version (WQPei, Cameron, 1999) and the Mayer–Salovey–Caruso Emotional Intelligence Test (MSCEIT V.2., Mayer, Salovey, & Caruso, 1999b). Results were characterised by instability, heterogeneity and inconsistency. Specifically, the EIS was not found to form the homogenous structure postulated by authors. Similarly, support was not found for the seven factor model of the WPQei. Large discrepancies exist between the one, two and four factor models described by Mayer et al. (2003) for the MSCEIT V.2. and the 21 components revealed at the primary level in the current analyses. Additionally, reliability statistics for the MSCEIT V.2. were less than optimal. Questions remain regarding the clarity, reliability and validity of the instruments examined.

The emotional context of self-management in chronic illness: A qualitative study of the role of health professional support in the self-management of type 2 diabetes

Background: Support for patient self-management is an accepted role for health professionals. Little evidence exists on the appropriate basis for the role of health professionals in achieving optimum self-management outcomes. This study explores the perceptions of people with type 2 diabetes about their self-management strategies and how relationships with health professionals may support this.

Methods: Four focus groups were conducted with people with type 2 diabetes:  two with English speaking and one each with Turkish and Arabic-speaking. Transcripts from the groups were analysed drawing on grounded hermeneutics and interpretive description.

Results: We describe three conceptually linked categories of text from the focus groups based on emotional context of self management, dominant approaches to self management and support from health professionals for self management. All groups described important emotional contexts to living with and self-managing diabetes and these linked closely with how they approached their diabetes management and what they looked for from health professionals. Culture seemed an important influence in shaping these linkages.

Conclusion: Our findings suggest people construct their own individual self-management and self-care program, springing from an important emotional base. This is shaped in part by culture and in turn determines the aims each  person has in pursuing self-management strategies and the role they make available to health professionals to support them. While health professionals'  support for self-care strategies will be more congruent with patients' expectations if they explore each person's social, emotional and cultural circumstances, pursuit of improved health outcomes may involve a careful balance between supporting as well as helping shift the emotional constructs surrounding a patient life with diabetes.