α-Actinin and Filamin Cooperatively Enhance the Stiffness of Actin Filament Networks

BACKGROUND: The close subcellular proximity of different actin filament crosslinking proteins suggests that these proteins may cooperate to organize F-actin structures to drive complex cellular functions during cell adhesion, motility and division. Here we hypothesize that alpha-actinin and filamin, two major F-actin crosslinking proteins that are both present in the lamella of adherent cells, display synergistic mechanical functions. METHODOLOGY/PRINCIPAL FINDINGS: Using quantitative rheology, we find that combining alpha-actinin and filamin is much more effective at producing elastic, solid-like actin filament networks than alpha-actinin and filamin separately. Moreover, F-actin networks assembled in the presence of alpha-actinin and filamin strain-harden more readily than networks in the presence of either alpha-actinin or filamin. SIGNIFICANCE: These results suggest that cells combine auxiliary proteins with similar ability to crosslink filaments to generate stiff cytoskeletal structures, which are required for the production of internal propulsive forces for cell migration, and that these proteins do not have redundant mechanical functions

Biochemical properties of Paracoccus denitrificans FnrP:Reactions with molecular oxygen and nitric oxide

In Paracoccus denitrificans, three CRP/FNR family regulatory proteins, NarR, NnrR and FnrP, control the switch between aerobic and anaerobic (denitrification) respiration. FnrP is a [4Fe-4S] cluster containing homologue of the archetypal O2 sensor FNR from E. coli and accordingly regulates genes encoding aerobic and anaerobic respiratory enzymes in response to O2, and also NO, availability. Here we show that FnrP undergoes O2-driven [4Fe-4S] to [2Fe-2S] cluster conversion that involves up to 2 O2 per cluster, with significant oxidation of released cluster sulfide to sulfane observed at higher O2 concentrations. The rate of the cluster reaction was found to be ~6-fold lower than that of E. coli FNR, suggesting that FnrP can remain transcriptionally active under microaerobic conditions. This is consistent with a role for FnrP in activating expression of the high O2 affinity cytochrome c oxidase under microaerobic conditions. Cluster conversion resulted in dissociation of the transcriptionally active FnrP dimer into monomers. Therefore, along with E. coli FNR, FnrP belongs to the subset of FNR proteins in which cluster type is correlated with association state. Interestingly, two key charged residues, Arg140 and Asp154, that have been shown to play key roles in the monomer-dimer equilibrium in E. coli FNR are not conserved in FnrP, indicating that different protomer interactions are important for this equilibrium. Finally, the FnrP [4Fe-4S] cluster is shown to undergo reaction with multiple NO molecules, resulting in iron nitrosyl species and dissociation into monomers

An interdisciplinary intervention for older Taiwanese patients after surgery for hip fracture improves health-related quality of life

Abstract Background The effects of intervention programs on health-related quality of life (HRQOL) of patients with hip fracture have not been well studied. We hypothesized that older patients with hip fracture who received our interdisciplinary intervention program would have better HRQOL than those who did not. Methods A randomized experimental design was used. Older patients with hip fracture (N = 162), 60 to 98 years old, from a medical center in northern Taiwan were randomly assigned to an experimental (n = 80) or control (n = 82) group. HRQOL was measured by the SF-36 Taiwan version at 1, 3, 6, and 12 months after discharge. Results The experimental group had significantly better overall outcomes in bodily pain (β = 9.38, p = 0.002), vitality (β = 9.40, p < 0.001), mental health (β = 8.16, p = 0.004), physical function (β = 16.01, p < 0.001), and role physical (β = 22.66, p < 0.001) than the control group at any time point during the first year after discharge. Physical-related health outcomes (physical functioning, role physical, and vitality) had larger treatment effects than emotional/mental- and social functioning-related health outcomes. Conclusions This interdisciplinary intervention program may improve health outcomes of elders with hip fracture. Our results may provide a reference for health care providers in countries using similar programs with Chinese/Taiwanese immigrant populations. Trial registration NCT01052636http://deepblue.lib.umich.edu/bitstream/2027.42/78259/1/1471-2474-11-225.xmlhttp://deepblue.lib.umich.edu/bitstream/2027.42/78259/2/1471-2474-11-225.pdfPeer Reviewe

Sensitive and low-potential electrochemical detection of hydroquinone using a nanodiamond modified glassy carbon electrode

© 2017 The Authors. The present work describes the sensitive and low-potential detection of hydroquinone (HQ) using a glassy carbon electrode (GCE) modified with nanodiamond (ND). The presence of ND was confirmed by high-resolution scanning electron microscopy, FTIR and Raman spectroscopy. The cyclic voltammetry results reveal that ND modified GCE has high electrocatalytic activity towards oxidation of HQ than unmodified GCE. In addition, the ND modified GCE shows a significantly lower oxidation potential towards CC than unmodified GCE, which is due to the presence of -OH functional groups in ND. The CV studies confirm that the redox electrochemical behavior of CC is a diffusion controlled electrochemical process on ND modified electrode. The ND modified electrode was able to detect the HQ across a linear response range from 1.0 to 78.0 μM. The limit of detection of the sensor was 0.19 μM. The sensor shows an appropriate selectivity in the presence of 20-fold concentrations of benzenediols and neurotransmitters. The practicality of the sensor is appropriate and shows excellent recovery of HQ in lab water samples

Determinants of urinary albumin excretion within the normal range in patients with type 2 diabetes: the Randomised Olmesartan and Diabetes Microalbuminuria Prevention (ROADMAP) study

In contrast to microalbuminuric type 2 diabetic patients, the factors correlated with urinary albumin excretion are less well known in normoalbuminuric patients. This may be important because even within the normoalbuminuric range, higher rates of albuminuria are known to be associated with higher renal and cardiovascular risk. At the time of screening for the Randomised Olmesartan and Diabetes Microalbuminuria Prevention (ROADMAP) Study, the urinary albumin/creatinine ratio (UACR) was 0.44 mg/mmol in 4,449 type 2 diabetic patients. The independent correlates of UACR were analysed. Independent correlates of UACR during baseline were (in descending order): night-time systolic BP (r (s) = 0.19); HbA(1c) (r (s) = 0.18); mean 24 h systolic BP (r (s) = 0.16); fasting blood glucose (r (s) = 0.16); night-time diastolic BP (r (s) = 0.12); office systolic BP, sitting (r (s) = 0.11), standing (r (s) = 0.10); estimated GFR (r (s) = 0.10); heart rate, sitting (r (s) = 0.10); haemoglobin (r (s) = -0.10); triacylglycerol (r (s) = 0.09); and uric acid (r (s) = -0.08; all p a parts per thousand currency signaEuro parts per thousand 0.001). Significantly higher albumin excretion rates were found for the following categorical variables: higher waist circumference (more marked in men); presence of the metabolic syndrome; smoking (difference more marked in males); female sex; antihypertensive treatment; use of amlodipine; insulin treatment; family history of diabetes; and family history of cardiovascular disease (more marked in women). Although observational correlations do not prove causality, in normoalbuminuric type 2 diabetic patients the albumin excretion rate is correlated with many factors that are potentially susceptible to intervention. ClinicalTrials.gov ID no.: NCT00185159 This study was sponsored by Daichii-Sankyo.Nephrolog

Laboratory layered latte

Inducing thermal gradients in fluid systems with initial, well-defined density gradients results in the formation of distinct layered patterns, such as those observed in the ocean due to double-diffusive convection. In contrast, layered composite fluids are sometimes observed in confined systems of rather chaotic initial states, for example, lattes formed by pouring espresso into a glass of warm milk. Here, we report controlled experiments injecting a fluid into a miscible phase and show that, above a critical injection velocity, layering emerges over a time scale of minutes. We identify critical conditions to produce the layering, and relate the results quantitatively to double-diffusive convection. Based on this understanding, we show how to employ this single-step process to produce layered structures in soft materials, where the local elastic properties vary step-wise along the length of the material