RMIT University

About: RMIT University is a education organization based out in Melbourne, Victoria, Australia. It is known for research contribution in the topics: Population & Health care. The organization has 40468 authors who have published 82923 publications receiving 1729499 citations. The organization is also known as: Royal Melbourne Institute of Technology & Melbourne Technical College.

Skeletal myocytes are a source of interleukin-6 mRNA expression and protein release during contraction: evidence of fiber type specificity

Abstract: In this study, we aimed to determine whether skeletal muscle cells per se are a source of interleukin (IL)-6 during contraction and whether IL-6 production is fiber type specific. Muscle biopsy samples were collected from seven males before (PRE) and after (POST) completing 120 min of continuous bicycle ergometry. Biopsies were sectioned and analyzed for the following: IL-6 protein detected by immunohistochemistry (IHC), IL-6 mRNA content detected by in situ hybridization, fiber type measured by either IHC or myofibrillar ATPase activity stain, and glycogen content measured by periodic acid schiff (PAS) assay. Fibers were qualitatively categorized according to glycogen content to one of five groups (1-5), with 1 being very low (LOW) and 5 being very high (HIGH) glycogen. Total fluorescence (PRE vs. POST) and glycogen-dependent fluorescence (LOW vs. HIGH) of IL-6 protein were quantitated using Metamorph software. Total IL-6 protein was elevated from PRE to POST exercise (P<0.05). At PRE, IL-6 protein was evenly distributed across all fibers at low levels, consistent with glycogen distribution. At POST, IL-6 protein was greater (P<0.05) in HIGH compared with LOW glycogen fibers, which coincided with type 2 fibers. IL-6 mRNA was distributed peripherally in all fibers at PRE. At POST, however, IL-6 mRNA appeared predominantly in type 2 fibers, which also had higher glycogen content (P<0.05). These data demonstrate that myocytes per se are a source of IL-6 produced during contraction. Our data also suggest that type 2 fibers predominantly produce IL-6 during muscle contractile activity.

Stroke Thrombolysis Save a Minute, Save a Day

Abstract: Background and Purpose— Stroke thrombolysis is highly time-critical, but data on long-term effects of small reductions in treatment delays have not been available. Our objective was to quantify patient lifetime benefits gained from faster treatment. Methods— Observational prospective data of consecutive stroke patients treated with intravenous thrombolysis in Australian and Finnish centers (1998–2011; n=2258) provided distributions of age, sex, stroke severity, onset-to-treatment times, and 3-month modified Rankin Scale in daily clinical practice. Treatment effects derived from a pooled analysis of thrombolysis trials were used to model the shift in 3-month modified Rankin Scale distributions with reducing treatment delays, from which we derived the expected lifetime and level of long-term disability with faster treatment. Results— Each minute of onset-to-treatment time saved granted on average 1.8 days of extra healthy life (95% prediction interval, 0.9–2.7). Benefit was observed in all groups: each minute provided 0.6 day in old severe (age, 80 years; National Institutes of Health Stroke Scale [NIHSS] score, 20) patients, 0.9 day in old mild (age, 80 years; NIHSS score, 4) patients, 2.7 days in young mild (age, 50 years; NIHSS score, 4) patients, and 3.5 days in young severe (age, 50 years; NIHSS score, 20) patients. Women gained slightly more than men over their longer lifetimes. In the whole cohort, each 15 minute decrease in treatment delay provided an average equivalent of 1 month of additional disability-free life. Conclusions— Realistically achievable small reductions in stroke thrombolysis delays would result in significant and robust average health benefits over patients’ lifetimes. The awareness of concrete importance of speed could promote practice change.

Effects of static magnetic fields at the cellular level.

Abstract: There have been few studies on the effects of static magnetic fields at the cellular level, compared to those of extremely low frequency magnetic fields. Past studies have shown that a static magnetic field alone does not have a lethal effect on the basic properties of cell growth and survival under normal culture conditions, regardless of the magnetic density. Most but not all studies have also suggested that a static magnetic field has no effect on changes in cell growth rate. It has also been shown that cell cycle distribution is not influenced by extremely strong static magnetic fields (up to a maximum of 10 T). A further area of interest is whether static magnetic fields cause DNA damage, which can be evaluated by determination of the frequency of micronucleus formation. The presence or absence of such micronuclei can confirm whether a particular treatment damages cellular DNA. This method has been used to confirm that a static magnetic field alone has no such effect. However, the frequency of micronucleus formation increases significantly when certain treatments (e.g., X-irradiation) are given prior to exposure to a 10 T static magnetic field. It has also been reported that treatment with trace amounts of ferrous ions in the cell culture medium and exposure to a static magnetic field increases DNA damage, which is detected using the comet assay. In addition, many studies have found a strong magnetic field that can induce orientation phenomena in cell culture.

Social media use and social connectedness in adolescents: The positives and the potential pitfalls

Abstract: As social media use is rising among adolescents, the issue of whether this use leads to positive or negative outcomes warrants greater understanding. This article critically reviews the literature related to this important topic. Specifically, we examine how social media use affects social connectedness in terms of three elements of adolescent development: sense of belonging, psychosocial wellbeing, and identity development and processes. Mixed findings are reported regarding the role that social media plays in fostering social connectedness, which suggests that young people may experience both positive and negative psychological outcomes. As a result, this article argues that online tools create a paradox for social connectedness. On one hand, they elevate the ease in which individuals may form and create online groups and communities, but on the other, they can create a source of alienation and ostracism. This article contributes to ongoing discourse in the area of educational and developmental psychology, and has implications for researchers and practitioners working with adolescents.