Nocodazole Treatment Decreases Expression of Pluripotency Markers Nanog and Oct4 in Human Embryonic Stem Cells

Nocodazole is a known destabiliser of microtubule dynamics and arrests cell-cycle at the G2/M phase. In the context of the human embryonic stem cell (hESC) it is important to understand how this arrest influences the pluripotency of cells. Here we report for the first time the changes in the expression of transcription markers Nanog and Oct4 as well as SSEA-3 and SSEA-4 in human embryonic cells after their treatment with nocodazole. Multivariate permeabilised-cell flow cytometry was applied for characterising the expression of Nanog and Oct4 during different cell cycle phases. Among untreated hESC we detected Nanog-expressing cells, which also expressed Oct4, SSEA-3 and SSEA-4. We also found another population expressing SSEA-4, but without Nanog, Oct4 and SSEA-3 expression. Nocodazole treatment resulted in a decrease of cell population positive for all four markers Nanog, Oct4, SSEA-3, SSEA-4. Nocodazole-mediated cell-cycle arrest was accompanied by higher rate of apoptosis and upregulation of p53. Twenty-four hours after the release from nocodazole block, the cell cycle of hESC normalised, but no increase in the expression of transcription markers Nanog and Oct4 was detected. In addition, the presence of ROCK-2 inhibitor Y-27632 in the medium had no effect on increasing the expression of pluripotency markers Nanog and Oct4 or decreasing apoptosis or the level of p53. The expression of SSEA-3 and SSEA-4 increased in Nanog-positive cells after wash-out of nocodazole in the presence and in the absence of Y-27632. Our data show that in hESC nocodazole reversible blocks cell cycle, which is accompanied by irreversible loss of expression of pluripotency markers Nanog and Oct4

Water and sodium intake habits and status of ultra-endurance runners during a multi-stage ultra-marathon conducted in a hot ambient environment: an observational field based study

<p>Abstract</p> <p>Background</p> <p>Anecdotal evidence suggests ultra-runners may not be consuming sufficient water through foods and fluids to maintenance euhydration, and present sub-optimal sodium intakes, throughout multi-stage ultra-marathon (MSUM) competitions in the heat. Subsequently, the aims were primarily to assess water and sodium intake habits of recreational ultra-runners during a five stage 225 km semi self-sufficient MSUM conducted in a hot ambient environment (T_max range: 32°C to 40°C); simultaneously to monitor serum sodium concentration, and hydration status using multiple hydration assessment techniques.</p> <p>Methods</p> <p>Total daily, pre-stage, during running, and post-stage water and sodium ingestion of ultra-endurance runners (UER, <it>n</it> = 74) and control (CON, <it>n</it> = 12) through foods and fluids were recorded on Stages 1 to 4 by trained dietetic researchers using dietary recall interview technique, and analysed through dietary analysis software. Body mass (BM), hydration status, and serum sodium concentration were determined pre- and post-Stages 1 to 5.</p> <p>Results</p> <p>Water (overall mean (SD): total daily 7.7 (1.5) L/day, during running 732 (183) ml/h) and sodium (total daily 3.9 (1.3) g/day, during running 270 (151) mg/L) ingestion did not differ between stages in UER (<it>p</it> < 0.001 <it>vs</it>. CON). Exercise-induced BM loss was 2.4 (1.2)% (<it>p</it> < 0.001). Pre- to post-stage BM gains were observed in 26% of UER along competition. Pre- and post-stage plasma osmolality remained within normal clinical reference range (280 to 303 mOsmol/kg) in the majority of UER (<it>p</it> > 0.05 <it>vs</it>. CON pre-stage). Asymptomatic hyponatraemia (<135 mmol/L) was evident pre- and post-stage in <it>n</it> = 8 UER, corresponding to 42% of sampled participants. Pre- and post-stage urine colour, urine osmolality and urine/plasma osmolality ratio increased (<it>p</it> < 0.001) as competition progressed in UER, with no change in CON. Plasma volume and extra-cellular water increased (<it>p</it> < 0.001) 22.8% and 9.2%, respectively, from pre-Stage 1 to 5 in UER, with no change in CON.</p> <p>Conclusion</p> <p>Water intake habits of ultra-runners during MSUM conducted in hot ambient conditions appear to be sufficient to maintain baseline euhydration levels. However, fluid over-consumption behaviours were evident along competition, irrespective of running speed and gender. Normonatraemia was observed in the majority of ultra-runners throughout MSUM, despite sodium ingestion under benchmark recommendations.</p

Energy intake and energy expenditure of pre-professional female contemporary dancers

Many athletes in aesthetic and weight dependent sports are at risk of energy imbalance. However little is known about the exercise and eating behaviours of highly trained dance populations. This investigation sought to determine the energy intake and energy expenditure of pre-professional female contemporary dancers. Twenty-five female contemporary dance students completed the study. Over a 7-day period, including five week days (with scheduled dance training at a conservatoire) and two weekend days (with no scheduled dance training at the conservatoire), energy intake (self-reported weighed food diary and 24 h dietary recall) and expenditure (tri-axial accelerometry) were recorded. Mean daily energy intake and expenditure were different over the 7-day period (P = 0.014) equating to an energy deficit of -356 ± 668 kcal·day-1 (or -1.5 ± 2.8 MJ·day-1). Energy expenditure was not different when comparing week and weekend days (P = 0.297). However daily energy intake (P = 0.002), energy availability (P = 0.003), and energy balance (P = 0.004) were lower during the week compared to the weekend, where energy balance became positive. The percentage contribution of macronutrients to total energy intake also differed; with higher fat (P = 0.022) and alcohol (P = 0.020), and lower carbohydrate (P = 0.001) and a trend for lower protein (P = 0.051) at the weekend. Energy balance and appropriate macronutrient intake are essential for maintaining the demands of training, performance and recovery. Whilst aesthetics are important, female contemporary dancers may be at risk of the numerous health and performance impairments associated with negative energy balance, particularly during periods of scheduled training

Teaching: Natural or Cultural?

In this chapter I argue that teaching, as we now understand the term, is historically and cross-culturally very rare. It appears to be unnecessary to transmit culture or to socialize children. Children are, on the other hand, primed by evolution to be avid observers, imitators, players and helpers—roles that reveal the profoundly autonomous and self-directed nature of culture acquisition (Lancy in press a). And yet, teaching is ubiquitous throughout the modern world—at least among the middle to upper class segment of the population. This ubiquity has led numerous scholars to argue for the universality and uniqueness of teaching as a characteristically human behavior. The theme of this chapter is that this proposition is unsustainable. Teaching is largely a result of recent cultural changes and the emergence of modern economies, not evolution

Screening for gestational diabetes mellitus selectively in a university maternity hospital

Aims: Screening for gestational diabetes mellitus (GDM) may be universal or selective based on risk factors. We audited selective screening with an Oral Glucose Tolerance Test (OGTT). Methods: Clinical and laboratory details of the first 200 women who delivered a baby in 2017 were analysed. Results: Based on national recommendations, 46.5% (n=93) had maternal risk factors (RF) and an additional 6.5% (n=13) had fetal RF. Nine women with RF, for unexplained reasons did not have their OGTT. Of the 95 who had their OGTT, the diagnosis of GDM was made in 27.4% (n=26). The diagnosis of GDM was made in an additional 8 women outside selective screening giving an overall incidence of 17.0%. Discussion: More than half of the women needed to be screened selectively for GDM. Compliance with the national recommendations was incomplete and thus the diagnosis of GDM may be missed even in an academic setting

Prevention of post-operative bleeding in hemostatic compromised patients using native porcine collagen fleeces-retrospective study of a consecutive case series

Various anticoagulant therapy regimes bear the risk of postsurgical bleeding events after dental extractions. Local hemostyptic measures, e.g., collagen fleeces, are applied by surgeons to prevent such bleedings. No standard protocol in prevention of bleeding events has met general acceptance among surgeons yet. The purpose of this retrospective study was to determine if post-operative bleeding can be prevented by suturing native collagen fleeces into extraction wounds immediately after teeth removal, regardless what anticoagulant regime is performed. A total of 741 extraction units were removed from 200 consecutive in-ward patients with or without alternation of different anticoagulant therapy regimes. Anti-vitamin K agents were the most prescribed drugs (n = 104, 52 %), followed by Acetylsalicylate (ASS) (n = 78, 39 %). Nineteen (9.5 %) patients received a dual anti-platelet therapy. Out of 104 patients receiving an anti-vitamin K agent (phenprocoumon), 84 patients were bridged, 20 patients continued to their anticoagulant therapy without alterations. Following careful tooth extraction, extraction sockets were filled using a native type I and III porcine collagen sponge (Collacone, Botiss Biomaterials, Berlin), supported by single and mattress sutures for local hemostasis. Post-operative bleeding events were rated according to their clinical relevance. In the post-operative phase, 8 out of 200 consecutively treated patients experienced a post-operative bleeding event. All of them had been designated for a long-term anti-vitamin K therapy (p <= 0.05), and extractions were performed under a heparin bridging regime (n = 6) or an uninterrupted anti-vitamin K agent therapy (n = 2). No bleeding events occurred in patients with ASS 100 therapy or low-dose LMWH therapy (p <= 0.05), or in patients with dual anti-platelet therapy (0 out of 24). None of the bleeding events put patients' health at risk or required systemic intervention. Sufficiently performed local hemostyptic measures, like the application of collagen fleeces in combination with atraumatic surgery, bears a great potential for preventing heavy bleeding events in hemostatic compromised patients, regardless of their anticoagulant therapy